Theres a few obvious things that you can do to prevent dirty records. Obviously washing your hands before you mix, never leave a vinyl out longer than it needs to be, I'm always suprised if I'm ****ed and leave the things on the decks over night, next morning they're totally covered in shit. Statics a right bastard!

Buying one of those vinyl brush things (got mine from HMV), just before you cue up hold the brush over the vinyl whilst the deck is turning, gets quite a lot of dust of for little time and effort. Also having your needles in good condition helps because they cut through the dust. ****ing exspensive though, I use concords and change the tips every year, 40 quid a pop!