I've had "use strict;" pounded into me enough times so that I really try to use it (except in some very short scripts). I also segregate my code a lot more, though I'm not sure if this is perlmonk's influence or just my own experience.
I guess the biggest thing is that perlmonks is my first source of perl information after the manpages. It's never let me down, and nearly every time I ask a question I get introduced to whole new realms of techniques. Perlmonks: worth the money.