I think you should get to know a person long enough to base your advances/moves upon. If they don't want to, then don't push it. If they want to, usually a slow, but aggressive way is the best course of action. Push for it, but do not seem desperate, and wait it out if you have too. You should know, through this elongated period, if you both want to, and if not, pull back. Just be steady, and no sudden changes. Take it casual my friend, and have no fear.