In my mind for any rotation 3 or more, I like to think of starting the snap with my back hip and shoulder because it tends to carry me off the lip smoother. The downside is the timing means I have to wait, wait, wait until the last possible moment to snap it around and sometimes I still mess up and end up facing 90 and getting the rotation but losing so much speed I'll knuckle badly.
If you are leaning backwards and it's throwing you off balance, this timing technique will also tend to help but make sure you aren't also putting your weight on the back foot. This will tend to make you throw your back shoulder up and around your head like a batter trying to swing up on a pitch which will tend to cork your spin. This could be why you are ending up biffing on the landing but without seeing it it's hard to say. Anyway, I'm sure cr0 will stop by and provide better info than I can but that sounds like what's happening to me.