A few ideas for you. Ferro rod in conjunction with #0000 (extra-extra-extra fine) steel wool and ..... dry tinder, inner tubes cut into tiny pieces, cotton balls and vaseline, jute twine that you"birds nest or fluff" out, fatwood. Get yourself a pencil sharpener, a carpenters sharpener works too for "pencil" sized sticks, makes nice small fire starter and sticks are easy to find. It takes awhile, but works pretty well.
Anyhow, just a few things I've messed around with and seems to work fine. Be advised, the #0000 steel wool burns very hot and very fast so be careful. Like others have said, square up the spine of your knife for ferro rods and shaving magnesium blocks.
Mike