Yo Eppo, here's one for ya.
When riding in preffered direction for backroll, have kite at 10:30/10:45, power up, realease front hand, edge real hard (upwindish), throw body into aggresive back roll with pop, after 180 degrees, mongrel bar towards ya (remember your only using one hand), kite will whip you up, as it is doing it's loop and throw you into a second spin, so becomes a double back with only one twist in your lines.
When done correctly, it is the most incredible feeling, if you try to back out half way thru, your gonna eat caca.
Have fun. Veebs
Disclaimer:, learning this may not be good for your ankles