I've always placed my trigger finger in "register" along the receiver of an AR-15 in a way that approximately feels like where I place it on a pistol. This ends up with my trigger positioned like this:
The problem I've had with this placement is that something coming into contact with my right hand (usually the ground) can cause me to accidentally press the magazine release. I've notice that a lot of other shooters use this position:
But, I don't like how close this is to the trigger guard.
This pretty much leaves only this placement:
This feels sort of uncomfortable and my finger ends up on the dust cover when its open, which is weird because I'm used to the register position always feeling the same way and my brain thinks there is something wrong when my trigger finger hits something unexpected. I assume this will go away with practice.
What does everybody else do, and do have you ever had any accidental mag release issues? (It happens for me most often when shooting through the bottom ports of a VTAC barricade.)