Try learn barspins, 180s and learn to fakie for a while without hops. Then once you've got them clean, learn 180 bars, 360s, 180 whips, downside whips and just go from there. Watch videos and try the tricks they're doing.
http://www.youtube.com/watch?v=2KrdBUFeFtY doesn't say what it's called but really fun when you learn how to do em. + when you get em whilst flying over a box/gap they're really cool and impressive.