The primary means of starting fire for European cultures over the last 1000 years (possibly longer) has been flint and steel. Building the flint and steel fire has become one of the sporting events common to black powder rendezvous. Because of this flint and steel sets and the knowledge required to use them are available to anyone who wants to learn the technique.
The four items needed to start a flint and steel fire are:
Flint, or some other hard rock.
A fire steel.
Something to catch sparks.
Tinder.
Flint has been the traditional stone because it is hard, and breaks into keen edged fragments. Other stones will work, particularly the quartz based minerals. Look for stones that break into relatively flat sections with sharp edges.
The steel is struck against the sharp edge of a hard stone which shaves off very small splinters of steel which are heated white hot by friction. To strike a fire hold the char on Top of the flint, close to the edge and strike the stone with a long sweeping downward stroke of the steel. Char cloth can be wrapped around the stone. When a spark catches in the char, a small glowing spot will appear. Blow on the spot gently and it will spread into the char material.
The most critical is number 3, the spark catching material. The most common material is charred cotton or linen cloth.
Char cloth is produced by heating in a low oxygen environment, producing a charcoal like substance. Get a metal can that can be resealed. Put the cloth to be charred in the can and seal it. Punch a small hole in the can and put the whole mess in a fire. Watch for smoke escaping through the hole in the can. When the smoke decreases slightly, remove the can from the fire and stopper the hole with a nail or something. After the can cools, look at the cloth. If it's dark brown, it wasn't heated long enough. If it falls apart at the slightest touch, it was heated to long. Experiment. The cloth needs to be 100% cotton, and free of dyes and other synthetics. The heavier the cloth, the better.
Another good material to treat in this way is very rotten punk wood. Wood so rotten that it can be broken off with your hands. Maple is the preferred wood, but others work well also. Gather several different types and see what works well. Experiment. Charred punk is not as consistant as cloth, some will catch sparks very well, some won't at all. If it does catch, it is next to impossible to kill. Don't throw away the charred punk that won't catch sparks, it'll be useful later.
Char material will glow, but it does not produce an open flame. That is the job of the tinder. Lay the glowing char in a birds next of fine dry tinder. Shredded paper, dry grass, and cedar bark all work well. Gently blow on the ember until the tinder bursts in to a flame.
On sunny days, a magnifying glass will get an ember going in the char material very easily. From there to getting the tinder going is no problem. The charred punk that you couldn't light with a spark will start this way.