Using the Walk Away Technique to Focus Her Attention on You
It doesn't have to be a special thing, or well-timed, or anything. Wait for a moment when you're hanging around with your love interest and she's not paying attention to what you're doing. If you're at her house and the phone rings or something.
Just get up and leave, don't say a word, and be sure she doesn't see you leave.
You've forced her to do a few things. First of all, she's going to look around for you if it is at all possible you could be hiding somewhere. Second, she's going to have to try and rationalize why you would leave without saying goodbye or saying anything.
For almost all women this will nag at her for quite a while, which also means she's thinking about you.
The second part of the "walk away" is to not try to come up with an excuse.
Next time you see her she will most likely bring it up, if not then she's not that interested in you anyway. Simply shrug and apologize without very much conviction.
All of this is building up your sense of mystery and makes you look like you must have something more exciting than her going on. Women want to be noticed, and when you just walk away it's like telling her that she's really not that important to you yet.
She will want to remedy that, usually by trying to get you to pay more attention to her, which is good of course.