Magnifying Glass / Lense: Used on a clear day, has a small chance to light a fire. Used on a sunny day has a large chance to light a fire. Can only ignite kindling or tinder reliably.
Kindling: Use survival to break down wooden objects into varying amounts of kindling with an axe, similar to knifing clothes to make rags. Has a higher chance to ignite when fire is applied to it than other wooden objects, but burns faster. Burns for only minutes, but has a decent chance of igniting other objects on the same tile.
Tinder: Use survival to gather this from grassy tiles, only in summer. Similar to kindling, however has a near 100% chance to ignite. Burns for only seconds, but has a high chance of igniting other objects on the same tile.
Flint: Apply with any steel item to create sparks, with a small chance of igniting nearby tiles. Can be targeted, but reliability increases with survival skill. Unskilled attemps liable to result in self ignition.
In short, renewable sources of fire that can be obtained fairly easily, however require skill to use effectively. And not catch fire. We can build cars! Why can we not punch a lense out of our glasses and light a fire with it?
EDIT: Turns out I’m a bit of a screwup, this was supposed to be in the library. Not sure exactly how it ended up not there, but there you have it. How does one get it moved?
EDIT: EDIT: I mean the drawing board. Derp.