For me, the area that works best is a ring around my belly button from 1"-3" away from the belly button. If you’re underweight, you should ideally be using a 45° angle, as you likely aren’t going to have the fat depth to comfortably do 90° with a 1/2" needle. You only need to keep the needle in for about 4 seconds after bottoming out the plunger; any longer is superfluous (and probably quite uncomfortable). I will say that while I highly doubt it’s relevant, I use 30G 1/2" needles and have never gotten any drainage from my E shots while following the steps I outlined in my original comment. But I’m also at a mid-healthy range weight, and don’t have trouble finding a fat pocket to inject into. I will warn you that thighs will likely have less fat, if you were injecting there. And I just remembered, depressing the plunger slowly may help (like over the course of 3-4 seconds), so if you were going fast before, then that may be something to try! Otherwise, I’d ask on the DIY community for advice, as I’ve never encountered this problem myself. My only further advice if nothing I’ve recommended works is to try intramuscular. It’s a very loose feeling with it being a deeper injection that it would be less likely to leak out; I don’t know if that holds up in reality.

And I feel like it goes without saying, but I may as well offer the advice: make sure the needle is fully inserted, and not partially inserted, because that could most certainly cause problems.