To easily do a 360 flip hippie flip, you need to do this:

Ollie and do a 180, then land in a nose manual. It will look like you are doing a funky looking manual. Ride up to a rail that is somewhat close to the ground. Do a nollie 360 flip right before you reach the rail, and, if you timed it right, you should do a 360 flip hippie flip. It may take some time to learn, but once you get them down, you should be able to do them consistently. This technique works best for lower rails.

Another way to do it is to do a 180, but not land in a manual. Set up for a nollie 360 flip right when your skater lands, making sure you bend all the way down, and do a nollie 360 flip right before you reach the rail. This technique works best for higher rails.