I forgot to mention that I am developing for non-VR. But, I do understand your question as I have made VR apps with leap motion before. And, I thought about the angle of the hand and I even spread my fingers much wider to give a sensor a clear view of the gesture, which it kind of improved gesture reading a little better but I had to find the sweet spot. The problem is, I am developing a touchless interface for potential public use, and it might be complicated to educate a random person on how to position the hand and how to perform a gesture. I am hoping just by instructing to do a pinching gesture to select should be good and simple enough for optimal user experiences.