I'm far from a aas newb but I STILL hate pinning glutes. Do it once a week and dread that day.
Quads are easiest for me since I don't have to twist around or look in a mirror. They're right in front and I can sit down and do it nice and easy. Shoulders are my 2nd favorite. Never tried pecs or calves or bis.
How about a vid on proper subcutaneous injection? I feel like I'm always doing it wrong even though its supposed to be so simple.