Telling filthy jokes to a girl you like is a great idea - especially if they so funny she cant help laughing really hard. The best are jokes where you can use words like "*******" and "blowjob", having those words said outloud to her, by you, is going to make the idea of doing them with you flash into her mind. Just be careful not to accidentally tell a joke that's too misogynist, unless you're trying to play the "jerk" card. I'm a very very good joke teller and this had worked in my favour so many times. It's also great for when you are in a group and it goes quiet, you can go "hey, want to hear a joke?", then tell an amazing one that makes everyone pay attention to you and burst out laughing at the end, easiest way to draw attention to yourself as the man to watch in the group for any girls present. EDIT: Dont take it too far though and crack jokes every five minutes - jesters and clowns dont get laid, wits do!