On difficult greens create a red light, yellow light and green light section and play your shot according to the risk involved
Hitting a guaranteed draw every time, to get around things like a tree, is simply learning how to set up for the shot with a closed clubface, closed stance, do not turn your body too early and allow your forearms to rotate through the shot more
Your choice of shot is dependent on what kind of lie you have in the bunker and how high the lip is