I just cut up old jeans into Altoids-tin-sized pieces, pack them tightly in an Altoids tin, then set it in the fire. I have no set rule on when to take it out again, just kinda when it feels right. You can get a lot of patches from jeans so experiment some to develop the touch for taking it out of the fire.

Another trick our wonderful Hawaiian member taught me was get some cotton window sashing cord from Walmart's craft area and light one end on fire. Let it burn a bit then snuff it out. The black area will readily take a spark which will then burn into the unburned part (hope that makes sense). Once you have your fire going snuff the burning end of the cord. Aloha keeps his in a piece of copper tubing to help snuff it.

-Blast