Don't use formulas, just mess around and see what sounds good.

Personally I don't use much reverb at all, especially not on drums.

Most of my kit I run via MIDI and don't have enough effects/channels for individual drum sounds but last night whilst messing around with a track I used the sampled snare off my TR606 (which sounds pretty weak) and stuck a reverb on it and it really made it sound fat and it had never occured to me to use reverb before.

If your going to use reverb on drums it can get really muddy sounding so try not to mix too much. Gated reverbs are also good for drums and try to use short decay times, but as I said before - just mess around, tweak those knobs and find something cool!

There's plenty of threads on this forum about compression.