What Ataki said. When I started here I thought Melange was the be all and end all of pipe tobacco. But then BoB got hold of me and I saw my meager two tin collection skyrocket to cover most (due to the shortage of FVF, Penz., etc) of the adored tobaccos. And I've barely scratched the surface. Look forward to many ah-ha moments while reading the forums, both in taste suggestions and technique. For those very new to the obsession, mastering the technique is the biggest bang for the buck imho.
As far as your specific question, I find it comes from the practiced balance of how much to really get it lit at which stage. I tend to get things really cooking on top for the first light, let it go out, tamp slightly, and then do the 'true' light much more gently. There's some bite risk with my start up method, but I find I have very little trouble keeping it lit from that point onwards. I figure the heat to start dries out the top layers enough to truly light, then as the bowl progresses, very slowly, the tobacco below comes into smoking equilibrium and burns much more evenly and continually. Drying the tobacco out as a whole has the potential to make the whole bowl burn very fast and almost tasteless (to me, though if it works for others there is validity).