From experience it mostly depends what you wear. I did the dumb thing at first and did my arms but yeah that got found fast. Thighs work but if you miss you can cause some problems. Best for me has been the stomach area or the chest, or even the back. The back has thinner skin then most of the rest or the torso (from my experience) so if you are aiming for draw that would be the best area. Higher upper arms can also work but it's risky.