I did not see this mentioned: Extra fine steel wool and a fresh 9 volt battery kick off a good fire, even in the rain. Put a few vaselined cotton balls on top of the steel wool, touch the battery terminals to the steel wool, and viola! Ignition! I carry this stuff in my hunting vest along with a magnesium block to add shavings to the cotton balls if the weather really stinks or to strike sparks if the battery craps out. Of course I also carry a few parafinned strike anywhere matches for less challenging conditions.
Another firestarter, if you're shotgunning, is to carefully take the powder out of a shell.
I pack this stuff and a few other things in my hunting vest and include a few sheets of folded up paper towel for hygiene and also fire starting.
The striker rod on the magnesium block doesn't work well with stainless steel as in many knives now days. Good sparks take high carbon steel. My solution was to add a 5 inch piece of hacksaw blade to the chain on the block. This produces good sparks. Plan B is to pack along a high carbon knife.
