Now, you only quaff preps if facing a hard(er) fight. The trick is knowing when the fight warrants the preps and which preps would be needed. Good warrior vets do it by instinct, but generally: don't quaff flight if you don't expect to be tripped, don't enlarge if no one's bashing, don't bother to put up stone skin if you're rushing a guy who doesn't know you're there, don't try to lag where you're outdamaged, don't be permalagged.
I don't know why some insist on putting up prot/stone/aura/shield for every fight, but against a good opp the only thing that gets you is their flee/word. The trick is timing your maledicts/disarms/burst/lag so that it looks like you might lose while you're controlling the fight. That's why you'd see jab/jab often from those in the know, they just whittle you down until flurry/parting blow will finish you off. If they see you lagging yourself, they'll go for the kill.
Know your build well. Sometimes you just can't take someone on and that's alright. For an easy example, don't go into shaman/warrior situations as dispel/bash will end you pretty much no matter what you're trying to do. Of course, sometimes that doesn't apply if you're say, a cloud warrior - they pretty much can't lag you and you get to control the fight. Conversely, that cloud warrior will be a sad splat going against a STSF elf/drow more often than not.
The biggest frustration for me is not actually preps, but roving gangs when you're one against three-six opps. As a non-villager warrior, you just can't do much as you bounce from gank to gank.