Call with a flush draw? Lead out and bet that hand, or even better RAISE. Put your opponents to the test and force them to make the decisions, not you. Also, if you do get called, you're hand is well disguised when you do hit, getting yourself paid off rather than coming to life when the flush hits making your check/call on the flop even more obvious to give away your hand. With this in mind, I'll check/call the flop in a heads up situation against and opponent I'm sure isn't on the flush draw in hopes that it hits and represent the flush with the standard weak play (imho) of flush draws.
Now I'm not saying that the aggressive play is what should happen on every hand. That's never true in poker. I'm just trying to make the point of just calling when you have draws, proper odds or not, is weak play and not winning poker. To many times I see people calling with draws and it's easy to take advantage of this when draws miss, and get away from people when they've obviously hit their hand. But if you must just call, look for at least 3:1, assuming you'll squeeze a little extra out of your opponents on the remaining streets when it hits.