good pick-ups help but for guaranteed no feed-back when playing with a floating hand you need to damp all unused strings with your fret hand. it's not that hard but it often means changing your hand position which can be daunting. plenty of players play real fast (and loud) with their hand "fixed" (usually at the bridge where it can best damp feed-back) try both, find what's best for you and stick to it.
apologies to FYL by the way, i meant no disrespect. Slainte.