Injection site problem

Ok so I've read the injection procedures, and googled Intramuscular injections and read the explanations on different websites ( they all have the exact same explanation) which is annoying, because the ventrogluteal site makes no sense. I land up on the glute medius, and when I find the dorsogluteal site, I land on pretty much the same spot, glute medius. The pictures don't help much either.
Does anyone have a decent link or something with good pictures, videos, whatever that makes sense. I know this is not rocket science, but I'd really prefer not to hit a nerve or something.
I'll also be pinning quads and shoulders since I'm doing EOD so I need a few sites for rotation.
I think I'm just being a pussy that I'm questioning things!

That's where I land up.




To much shit going on, that I'd prefer not to stick a needle into.

www.spotinjections.com

Just when i thought pinning was becoming a piece of cake......This AM i did a jab and i must of hit something in my quad cause i almost hit the ceiling!!!! FML

I'm sure you've seen many of these, but this was the video I used:



I very rarely have issues with my quads, but I have found that sometimes you'll be a cm to the left or right and it hurts bad whilst piercing the skin layer. For the glutes, I can only get to the right hand side one (left hand not so coordinated). I generally find that the needle enters a bit of an angle, probably due to the way i'm standing. I personally don't like pinning in the delts. Muscle is really small in comparison to the quads and glutes, and its much harder to judge the depth you need to go.