RV designers face a difficult task of balancing available space, cost, and usability. You can't usually do much about the overall floor plan, but you can sometimes make smaller improvements to existing closets and cabinets to improve convenience and usability. Interior storage areas include closets, drawers, and cabinets. Exterior storage areas are usually called compartments.
Tent campers don't usually have a lot of cabinets to deal with, but some of the suggestions given in this article might be applied to a "chuck box", that is sometimes useful to tent campers as a portable kitchen.
How you organize your stuff in your RV cabinets and compartments will make a big difference in usability. Adding a permanent or temporary extra shelf inside can make retrieving items more convenient, especially in large or deep cabinets. Plastic bins to corral small items are quite helpful. Without them small items tend to shift during travel and may come tumbling out in an avalanche when you open the door when you get to camp or simply get lost in a jumble of stuff in the bottom. Plastic shoeboxes are a convenient size to corall lots of the stuff we squirrel away in our RV cabinets. You ca also use cardboard boxes buy plastic is more durable and does a better job of containing spills if something gets broken.
Adding lights to dark closets or cabinets is a fairly easy and inexpensive upgrade. Automatic lights in closets are particularly useful. They can be hard wired into the vehicle's 12-volt electrical system or battery powered. They are usually controlled by a plunger type switch that turns the light on when the door is opened and turns it off again when the door is closed. Closet light kits are sometimes available from RV stores.
Battery powered LED lights are really easy to install in just about any closet or cabinet and do not require any wiring. They can usually be attached using double-sticky tape so you don't even need a screwdriver. My preferred choice are "tap lights", which are turned on or off by simply tapping the lens but versions with normal switches are also available. The only down side to tap lights is that shifting contents inside the cabinet could turn them on during travel and run down the batteries. Fortunately, LEDs don't draw a lot of power so if they do get accidentally turned on occasionally it probably won't be much of a problem. Mounting the lights high in the cabinet minimizes the chances of contents striking them and turning them on accidentally and gives you the best illumination. You usually get best coverage inside the cabinet by mounting them inside the front of the cabinet. The little LED lights that look like a light switch are good option for closets and large cabinets. They are extremely bright and the switch, which is like a normal household light switch isn't as likely to get flipped by shifting contents.
Deep cabinets can benefit from the addition of sliding drawers, bins, or shelves. Some luxury RVs come with sliding shelves or drawers in outside cabinets. This is especially useful since these large spaces tend to accumulate a lot of stuff and it can be difficult, frustrating, and time consuming to have to dig through multiple layers of stuff to find what you're looking for. Another good candidate for sliding shelves are the deep, narrow "pantries" in some units. Having the space to store canned goods etc is a real boon -- until you have to try to grab that can of chili from the very back of the top shelf! Adding sliding shelves to these cabinets is fairly easy and not too expensive, unless you opt for fancy self-closing slides and expensive hardwood shelves. Simply cut a shelf just wide enough to fit through the open door and slightly shorter than the depth of the cabinet. You will sacrifice about 1" of height for each shelf, but the gain in access and convenience is well worth it. To make it easy to pull the shelves out, drill 3/4" or 1" hole in the middle at the front of the shelf or cut the shelf short enough to add a handle. You may be able to find pre-finished shelves that closely match existing wood or stain common pine shelving to match. You might want to add a not-slip shelf covering to help keep contents from shifting and rattling. You could also add plastic bins to further contain small items or group like items for convenience and containment to prevent shifting during travel so cans don't fall out the back when you slide the shelf open.
Speaking of plastic bins, they can be used to good advantage in just about any cabinet to group and contain items. Translucent bins or baskets with holes you can see through will let you glimpse the contents without having to remove them from the cabinets. Bins can sometimes be stacked which gives you more options for organizing and accessing items. Instead of having to move a half dozen bottles to get to what is behind them you can just move one bin, get what you need, then put the bin back in place. Another benefit of using plastic bins is they will often capture spills to they don't spread throughout the cabinet or drip out the door. I wish I had been using plastic bins when a bottle of green food coloring tipped over and spilled in one of my galley cabinets. It leaked out and left permanent streaks down the face of the otherwise pristine and beautiful oak cabinet. It is also a lot easier to clean sticky spills from a plastic bin than it is to scrub them from a cabinet shelf. Being able to take the bin out and thoroughly wash it with hot water is much nicer than scraping and scrubbing in the confined space of the cabinet. In the worst case scenario you can always throw the contaminated bin away and replace it with a sparkling clean new one. Plastic bins are almost essential for storing extra motor oil and other automotive chemicals in your outside compartments. The bins make getting things out much easier and they are much easier to clean when something spills. Confining spills will help prevent contamination of other contents. It can be really nasty if your fresh water hose gets soaked in spilled motor oil or antifreeze, but storing potential offending liquids in plastic bins can prevent this from happening. Of course, it is better to keep your water hose in a different place than oil and antifreeze -- if you have enough room to do that.
Cabinet hardware (hinges, latches, and pulls) do eventually wear out or break down or may be damaged by accidents or abuse. This is especially true of the light weight plastic catches often used in RVs. They are pretty easy to replace, if you can find an exact replacement. Finding and exact match for cabinet hardware on older units may be a problem and you may have to adapt new hardware to solve the problem. Avoid damage in the first place by NOT slamming doors or otherwise abusing the hardware. Store heavy items only on bottom shelves where they can only slide against the door and not catapult into it. Using non-slip shelf lining will reduce sliding too. Take a second or two to make sure there is nothing in the way before closing the door. Anything that interferes with the door closing completely and smoothly could damage the hinges, latch, or the structure of the door itself. That includes things that protrude past the shelves or get caught between the door and the frame. As always, an ounce of prevention is worth a pound of cure. You can probably get replacement hardware for newer units at your local RV store or through the dealer or manufacturer, but you'd have to be really lucky to get an exact match for older units. For them you may have to scour junkyards for units of near the same vintage. Sometimes you can find matching hardware even in different brand vehicles than yours if they're about the same vintage. You might even find suitable replacements at your local hardware store or home center. If you can't match hardware exactly, one option is to replace all the hardware so everything still matches. Fortunately, hardware isn't terribly expensive.
Normal wear and tear will affect hinges and latches and many problems can be resolved by tightening hinges and adjusting latches. If the screws have pulled out you may be able get them to hold again by inserting a wooden match or toothpick into the hole and reinstalling the screw. If that doesn't work, sometimes a larger size screw will solve the problem. You can also get kits to repair screw holes. They consist of a cone-shaped tool for enlarging the hole and several wooden cones. You ream out the hole and glue a cone into it, then drill a small pilot hole in the cone and reinstall the screw. This works pretty well in solid materials like cabinet and door frames but not so well in paneling. One way to solve stripped screw problems in paneling is to use molly bolts, that have components containing a threaded nut that expand behind the paneling. Some have spring-loaded "wings", others are slotted cylinders that collapse and spread out as the bolt is tightened, gripping the paneling from behind.
Some extra large cabinets may benefit from adding more shelves. Make sure you don't create small spaces that will be difficult to get things in and out of. Shelves may be added permanently or installed so they rest on rails and can be easily removed if you need a taller space. Wire racks can often be found in houseware departments that can be used for temporary shelves. I've even seen folks make shelving from styrofoam insulation slabs to hold light weight items like clothing. Adding a shelf to a very tall cabinet can often double the usable space.
Non-slip shelf lining can help keep items from moving around during travel and reduce rattles. Keeping things from sliding around as the vehicle moves will help prevent damage to the contents and the cabinets and minimize unwelcome noise. Be creative in protecting and securing your items. One woman used colorful socks around glassware to prevent them from constantly banging into each other during travel. Another cut holes in styrofoam blocks to anchor her fancy glasses. Non-slip shelf lining can also be cut into smaller pieces to pad cookware to reduce rattles and prevent damage to the Teflon coating on pots and pans.
Some catches and latches aren't up to the task of resisting the forces of contents shifting during travel and pounding the door. Weak latches will allow stuff to fall out during turns. You may be able to upgrade the latches to something more substantial. You can also limit movement of contents inside cabinets using spring-loaded braces like those designed for refrigerators. Sometimes you can tie adjacent door handles together with mini-bungee cords to keep both cabinets closed. Another option are the "baby-safe" devices used to prevent little children from opening cabinet doors at home. Of course proper loading of cabinets to minimize weight and possible shifting is always a good idea. I have seen some creative owners install "thumb locks" for positive latching. These require drilling only one hole. The latch swings up inside the cabinet to secure the drawer or door. Done right they even look OEM professional.
Top-hinged outside cabinets are more convenient to use if there is a latch to hold the door open while you are accessing the cabinet. If your RV doesn't have these convenient latches they are fairly cheap and easy to install. Often they can be screwed to the side of the RV but the preferred way to attach them is using pop rivets. Take care to properly align the latch before you being drilling. Some latches may simply catch the edge of cabinet; others are designed to reach over the lip and catch inside the frame of the door.
Some cabinets have gas assisted struts to hold them open. If these become worn, bent, or damaged they may have to be replaced. If your RV doesn't have them and you would like to add them, they are usually fairly inexpensive to buy and not too difficult to install. Sometimes the screws attaching them to the cabinet and/or the door may get loose. If the hole is stripped so the screw won't tighten, try sticking wooden matchstick or toothpick in the hole with the screw to take up the slack. Badly stripped holes might be repaired using special plug kits, available at home centers and hardware stores. They consist of wooden cones and an auger to shape the holes to fit the cone. Glue the cone into the hole and let it dry completely, then drill a pilot hole slightly smaller than the diameter of the screw and reinstall the screw. Note, this will only work if the screws go into wood to hold them. Some exterior cabinets may have thin aluminum or fiberglass skins. To repair stripped fasteners in these, replace them with molyscrews.
When loading your cabinets, try to put light items in the upper cabinets and keep heavy items (like canned goods) in the lower ones. This has several advantages. For one, it will be less stressful on your body lifting light items than heavy ones into overhead cabinets. A second major advantage is light items will be less likely to become unguided missiles if a door come open during unexpectedly violent maneuvers. And finally, by avoiding putting too much weight in overhead cabinets you decrease the likelihood that the cabinets will come loose from the wall and or ceiling. Overloading overhead cabinets often leads to failure of the support systems and then you face a serious and potentially expensive repair.
RV closets sometimes have special closet rods that use proprietary clothes hangers to keep articles from falling off the rod from rough roads or unusually violent maneuvers. If yours does it can be tedious to switch hanging garments from their normal hangers to the special hangers and back for each trip. To keep hangers secure on a standard closet rod I've found a clean, dry car wash sponge fits well between the top of the rod and hangers and the ceiling and will hold the hangers in place without adding too much weight or interfering very much with hanging or removing clothes from the closet. If your RV is short of dresser drawer space, as many are, you might want to add one or two plastic drawers at the bottom of the closet. Unless it is unusually short, there should be space available underneath the clothes you hang in the closet.
Make it better!