Anchor a Song
Ok, I'm not a professional DJ or anything of the sort, but I do have a tip that seems to work quite well.
When I'm with a girl in the car I'll search through the stations till I find a popular song that is fairly new. Then I start singing along really badly and make a fool of myself.
I go off key and make my voice crack. I'll even nudge her and get her to sing too. I just try and make sure that it's real memorable, all the while she's laughing.
Now for the next few weeks, every time she hears that song she'll think of me and that day we spent together (make sure it was a fun one). She'll keep reliving those happy memories every time she hears the song.
I've done this a few times and a few days later I'll be driving and hear the special song (by the way, it works both ways -- I get reminded of her too) and she'll call me 10 minutes later!
What a coincidence right? WRONG!
Let me know how this works for you.