Just don't mention anything about a relationship or whatsoever. Make sure your pickups are always about having fun.
For instance, if you take a chick out to dance on a saturday night. That's all about fun right? If you two end up in bed together, make sure that between dancing and humping, you did not say any AFC shit like. "I could so fall in love with you tonight..." (I actually used this one
) This way you will both understand that having fun became sexual. No big deal. The next challenge is of course, if the sex was good, how do you make them come back for more... this is always tricky. Sometimes you can't prevent chicks from thinkin "OK this was a one-night thing: stupid!". So prepare yourself for the fact that some of them won't come back.
At the other hand, if you had casual fun and made the HB feel really comfortable about a night and the sex was good, then you can re-arrange the same kind of dates. Just never lie about your intentions. If you ever get caught lying in this kind of PU process, you're usually out of the race.
good luck
grtz
Bucc