when im working on a d&b track, i normally start by searching through hundereds (if not 1000's) of snare samples looking for one that has the right sound to it.... i'll then pick all other beats to match the snare
but having said that, i can save it, come back the next day and realise ive picked a shit snare after all that
but anyway, start with a good snare as your dominant one... if it needs something.... say some low end kick.... layer it with a snare with the right low end.... its a good idea to filter off some of the highs though and adjust the envelope so the snares match........ if it needs some high, layer one with some nice high, and roll off the low end
the reason being, if you have to many sounds layered without any filtering/eq'ing or env adjustment.... it can get very messy
other than that, i personally like to run them through a tube sim to give some warmth, eq and then give them some very subtle reverb.... but only once i have perfected the sound..... its by no means a cure for weak sounds