Couple thoughts for the OP:
1. Neutral buoyancy is probably more important than practice on this one. If you're always bouncing along the bottom and suddenly are OOA, you're going to have to swim that rig up. That may not be doable.
2. Always remember to stop, think and then act. When you're first OOA, evaluate options quickly and then do what you're trained to do. In my neck of the woods we had an experienced diver who died from lung overexpansion when they ascended from 60' in a rush because they had a (rare) first stage failure. I don't know the whole story, but I think there was a buddy at least within 60'. And they held their breath. It wasn't being OAA that killed them, but panicking in response and breath-holding. And this was not a newby.....