quads are my favorite, gluteus minimus is the most painless, gluteus maximus is good but readark_sideng around takes some getting used to, delts are ok but like your ass it takes a few tries to perfect the one handed pin.
If your sticking to 1ml and under you can pretty much pin anywhere. Larger dosages (1ml+) are recommended to be in larger muscle groups such as glutes and quads.
