This. It looks, feels and sounds foolish and mall ninjaesque (yes, I make up words) but I have practiced drawing my gun properly from my IWB, shoulder holster and BH Serpa thousands of times each. And each time I do it I make a point to follow the "Booger hook off the bang stick" rule. If it becomes so ingrained that you cannot force yourself to place your finger in the trigger guard until you're on target....you're almost there, practice a bit more. It also has the advantage of informing you what the limitations of time and position are in reference to your chosen carry method and cover clothing.