girls prefer a man who WANTS them - not a man who NEEDS them.
When they text you, go make a sandwich, then respond.
When they ask you out, accept, don't jump.
When making out, stop to go get a drink and leave her completely baffled why you're not begging her to get naked.
You won't get laid that night (or maybe you will), but you'll be IN permanently if you leave HER with blueballs and wanting more.
have a little game, play the numbers/volume game. Flirt with 10 girls and hang out with 2. the other 8 will be wondering why you haven't asked them out yet, doubting themselves and waiting, maybe even going so far as to ask you out.
These rules also apply to ladies. Don't appear too eager.