Need advice on self-aspirating

Everyday it was a struggle to try to get my AAS workout partner(doing the same cycle I am) to inject for me. I couldn't do it since it was a 21g needle. He wasn't taking these substances seriously and missing injections. Fed up with him, I finally took it upon myself to get the job done. I bought some 25g needles from Lion and did my first self-injection, deltoid. It slid in great. Now after I stick I can't wait to do it again. Only problem is that I'm having a hard time aspirating when I'm doing side area's like delts, ventroglutes, glutes, and tris. I hold the top of the syringe with my thumb and pull back with my index and middle finger. Any advice?

I know shooting these areas and trying to aspirate is difficult. The only thing I can say is the more you practice the better you will get.

I was thinking about holding the syringe with my hand and resting the end on a stationary object and slowing moving back until the aspiration is successful. Not sure how well that will work out with muscle tensions.

You litterally only need a tinly flick of the thumb to aspirate, you do not need to drag the whole syringe back to find blood.

if you hit an artery/vein, it'll be relatively easy to pull the plunger back and watch the tube fill up with blood... but if you tug with your fingers and feel a good amount of resistance, then you're probably good to go...you dont always have to wait for an air bubble to come.. especially when at an awkward angle