The first step in building most fires in fireplaces, stoves, or campfires, is setting up the tinder and kindling. So, exactly what is tinder and kindling and where do you get it? How do you use it?
Tinder is finely shredded fuel that can be easily ignited by a match or other fire starter. Some commercial flint and steel fire starter systems include a magnesium rod that can be scraped to get shavings that are easily ignited by sparks from the flint and steel. Magnesium shavings also have the advantage that they are not affected by moisture so they can be lit even when wet, a nice feature if you are trying to start a fire in the rain. Other common materials used as tinder for building fires includes dry grass, leaves, or weeds, pine needles, paper or cloth, real cotton balls, and wood shavings. Tinder needs to be very dry and very fine. Dry, crumpled newspaper makes excellent tinder. Real cotton balls, not synthetic ones, work well (synthetics melt instead of burn). Natural sources of tinder (dry grass, leaves, weeds, pine needles, etc) might need to be rubbed between your hands to grind them down into finer pieces that will light easily,. While you often find bundles of fire wood and kindling for sale at home centers and near campgrounds, tinder doesn't show up nearly as often. I guess they just expect you to make or provide your own. One really good source of tinder is something call fat wood. You can sometimes find it for sale where firewood is sold. Fat wood is pine heartwood that is is super saturated with resin. It occurs naturally in the rotting stumps and tap roots of dead pine trees. For starting fires without matches your tinder needs to be something that can be ignited by a spark, like paper, cotton balls, magnesium shavings, or very fine and dry grass or wood shavings. If using cloth avoid synthetics which are likely to melt instead of ignite. Cotton, linen and wool are good choices. Dryer lint from synthetics will most likely melt but lint from denim, cotton, linen, and wool will work very well.
Tinder is usually formed into a tinder bundle that can be ignited and positioned in your fuel stack to ignite it. You can also place it under your kindling before you light it.
Kindling is the next size of fuel for your fire. A good size for kindling is 1/4" thick, small twigs or 1' wide x 1/4" thick pieces split from your firewood. Softwoods are usually easier to light than hardwoods. Hardwoods are often desirable for the main fuel because they tend to burn hotter and give off more heat per volume than softwoods, but for kindling it is a good idea to have something that will light easily. You can usually split kindling off pieces of commercial firewood using just a hand-held hatchet. Be sure to hold the piece of wood with a stick instead of your fingers. Sticks won't feel the pain and are a lot easier to replace than you fingers if your accidentally chop in the wrong place!
If you plan to use flint and steel or a fire piston to start your fire you might need to bring some prepared tinder with you. It isn't always easy to find dry materials in the wild that are suitable for starting a fire without matches. Real cotton balls (not synthetic cosmetic wipes) and char cloth are easy to prepare, light weight, and take up little space in your pocket or pack. For starting fires with matches and lighters you can use dry grass, weeds, leaves, pine needles, or wood shavings. If these are really dry they might work for starting fires using flint and steel or rubbing two sticks together. Personally the only time I would want to start a fire by rubbing two sticks together is if one of them is a match!
Some types of fire starters might include tinder. The ones you make at home using paper egg cartons and wax usually contain shredded paper, sawdust or wood shavings that, together with the paper egg carton, comprises a bit of built in tinder. Sometimes it is enough to get things going but more often you may need to put more tinder around it to get enough flame to ignite kindling. Most of the commercial fire starters I've seen are designed as large ignition sources (think a really big match) and don't include a lot of tinder. So plan on using enough tinder and kindling even if you are using fire starters.
Tinder is usually formed into a kind of birds nest shape about the size of a softball to make a good base for starting a fire. There should be an easy place to ignite it, usually a kind of thin area along one edge or a hole in the middle. When igniting tinder using flint and steel or a fire piston you will need to be able to blow on the embers until they begin to flame up enough to be self sustaining. Many people like to hold the tinder bundle in their hands. Always use heavy leather gloves or a leather pad to protect your hands if you choose this option. Unless you are practiced in doing this, set the tinder bundle on a fireproof surface while getting it going.
Kindling is the next step after tinder. Kindling is small twigs or little pieces of fire wood, sometimes as small as a wooden match with larger pieces as thick as your fingers or even your thumb. Pieces larger than your thumb are usually too large for good kindling. Kindling is often made by splitting larger pieces of firewood but could be comprised of branches too large to be used for tinder. Split kindling tends to ignite and burn more easily than natural branches. You can sometimes buy bundles of kindling along with bundles of firewood. The only real difference is how thin the pieces have been split although sometimes kindling will also be made of softwoods even when fire wood bundles are made of hardwoods. Split kindling will usually be up to about 1'' wide and 1/4" thick. Softwoods generally light easier and burn faster than hardwoods, but hardwoods typically put out more BTUs of heat and may last longer. Yeah, I know, I already said all this, but it really is worth repeating. I like softwoods for kindling because it lights easier. Ultimately your choice of firewood will probably depend mostly on availability with price being second and BTU content third. Given availability and a good price, hardwood will give you more heat per volume than softwood.
Once you have setup your tinder bundle and kindling you will want to build your main campfire fuel stack around it, using either the log cabin (square) or tipi (cone) method. As an alternative you might want to use a top-down method where you stack the kindling and tinder on top of fuel stack. Building such a fuel stack is similar to the log cabin method but instead of simply building a square frame around the tinder and kindling you stack several layers of fuel leaving gaps between the pieces and stacking alternating layers in opposite directions. A top down fire will last longer without needing additional fuel, which can be useful if you have other tasks to attend to while the fire burns. For more about the top down method see my previous post on How To Build A Campfire Safely.
Light 'em up!