Second handy hint, if an enemy is about to die and there are other enemies around that need to be killed, I.e. Boss fights with adds, etc. If your Rupture is running low, just pour all your CPs into the largest Rupture you can, it gains the vast majority of your energy back when the enemy dies, and you can move to the next enemy with a fully loaded gun. Try to use you better judgement here though, if you're about half way through your energy or your SnD is about to fall, then use those CPs in an Env. It's completely situational.