I played a troll for the first time today too. Fun, but he can get hungry real quick. For regular classes, once I get hungry I would start feeding off of rats, wolves, and bats for as long as I can before consuming any of my inventory's food. Also, as was stated before, it's best to use you scrolls and potions one time as soon as you get them. Save your teleports and blinks for the gang bangs, keep your identifies for rings and amulets, and save your detect curses when you have many items.
Also beware with the teleport. On one of my games I accidently teleported into a small room with no stairs or extra teleportation scrolls. I was pretty much forced to start a new character.