lv2dive
Formerly known as KatePNAtl
Just get a pair of those triangle-shaped rubber fin-keepers (Riffe makes nice ones, better quality than Trident; $8 or $9), squirt them with some silicone spray to make them easier to don, and your Turbo soles will be locked down and never pop your fins off (you put them on over the Turbo soles, so they are inside your fins).
This is good advice for the majority of situations but again back to the fit... if the turbosoles are too big, fin keepers (alone, anyway) may not help. In my case, fin keepers made the situation worse. The only thing that worked - and I tried several - was filling the turbosole up with enough material where it wasn't ridiculously too big.