join a wedding band - sounds cheesy as hell, but it works, besides the fact the money can be decent (hey, lets not get into sellout status here, bills need paid!) it also improves your technique & keeps you thinking since the reality is you'll almost always be learning new songs and gives you a whole new perspective on playing!
as a drummer though (meh, who am i kidding, i haven't played in years!) the best thing i found was to play atleast 10% of the time left handed - really tunes up your independance and stops you getting complacent since nothing screws with your mind more than everything being backwards, after that you'll pretty much be able to play through anything!