Your Heelflip have to be really good. Some people say this is easier than a double Kickflip but whatever.
Setup like you would for a Heelflip. Oh yah you have to be able to spin the double Heelflip decently before you continue reading. Pop down as hard as you can and with your heel kick it out as fast as you can so that it hits the outside concave and flips really fast. Tuck up a lot and when you pop try to jump over the board a lot. If you start coming down to the ground before you finish then try again. I find it is super hard to land this when you don't finish spinning before you start coming down. Since it spins so fast you have to kind of guess when its down the double Heelflip. When you think its done then extend your legs and try to catch it.
Click Here to View the Video – Max Smith