The second stage of fire building past initial starting flame is MUCH HARDER for us on the coast than getting initial flame. It is really hard to get a self sustaining fire going.
That is experience talking! I think it is true to a certain extent everywhere and is the most often overlooked aspect of firebuilding. I don't know what world the "tinder to kindling" people are living in, but I know I've never been there. It always takes me a much more gradual progression of fuels with ample attention paid to building a good base of one size of fuel before trying to ladder up to the next one. All the different tinders I have tried work pretty well but none of them have been magic bullets that allowed me to ignore the real work of getting a fire to the self sustaining point.
For initial fire lighting, I carry 2" squares of bicycle inner tube. A single square will usually burn for about 3 minutes. That lets me carry a whole bunch of "starts" in a really compact and non-messy package. For backup, I carry trioxane. It's been a while since I've seen trioxane that wouldn't light as TAK mentions but I have seen it.
Evan makes a good point. All to often I see people pay lots of attention to tinder only to watch their fire smolder and die. Some call survey peg size wood "kindling" and to me that is more of a sustainable burn size fuel once the fire is really going.
I use what I refer to as micro kindling. Fatwood if available or at least dry wood that is toothpick to match stick size in diameter. Then I progress up to pencil size, then to thumb size and so on. It takes one heck of a fire to throw big wood on and have it sustain.
The necessity of having an ax or splitting knife is that the dry wood may only be available well inside a standing dead tree or branch. Splitting tools also allows you to have small wood to feed the fire with. Especially in a wood stove, I like to add small wood with large wood for a more complete burn.
There is no magic bullet, but lots of practice in the worst conditions you can find will prepare you for when the fire might be a matter of surviving.
Carry a good fire kit and like Dan said, gather pitch balls, pitch wood etc as you travel so that when you get to camp at least some of the essential burning material is at hand.
