So I've only been playing for a few days since my friend showed me the game but it would seem to me that one of the most effecient ways of keeping yourself ontop in the air would be to get a hand onto your opponent and hold them then alternate between extending and contracting the arm that your grabbing. just a thought

there are WAY too many ways to keep yourself above your opponent. Not just one :P

Something related - I've found that an effective way of keeping a grabbed opponent at arm's length is to extend elbows, contract wrists. This could help when attempting to lift an opponent up or flip them over. Certainly an effective Sambo hold is to contract one knee and get low to the ground, then use the aforementioned method combined with asymmetrical arm movement and torso movement to tip your opponent over.