try a forward apparently all you need is balls to do them and a good jumping skill, but if you can sail off the wind a bit and jump high enough to get your fin out of the water then your set,
i havnt had a solid day of good conditions to try and learn them, but i can do the basics.
first you need to practice them in light wind off the plane and out of the footstraps / harness. move your back hand far back down the boom , and sheet in look back toward the clew and tuck your legs in it also helps if you push through your front hand you will then do a elaborate catapult and land on your back unharmed

heres a where i read all that . . .
http://www.roynbartholdi.com/windsurf/ws_move_loop_learn1.htmsecond step . . .
www.roynbartholdi.com/windsurf/ws_move_loop_learn2.htmand finally when your balls have tripled in size and youve drank 4 cans of redbull ,
step 3 . . .
www.roynbartholdi.com/windsurf/ws_move_loop_forward.htm 
i heard that if you head upwind when doing one , the loop will be very upright , like end over end , and if you do it off the wind then it will be more flat and stable.
im hanging out for the day i get the right conditions to try it
