After locating it, standing up, I always lean to the side that I'm not injecting as to take the weight off the injection side to relaxe the muscle. Seems to help for me atleast.
Easiest way....if you want to pin right ventro, stand up and rotate your upper body to the left. The bulge of muscle that pops up is ventro glute. Aim for the middle...relax and move your weight to the left to take tension off the muscle and shoot.