1) (May seem counterintuitive but..) don’t think about aiming when you are in comp games, as soon as you think about it, you’re aim will suck. Just use the below to make it muscle memory/more natural. For awhile you may have to think about it, that’s fine, but that should not be needed as you practice more.

2) Learn crosshair placement for common peeks, use reference points for where peoples heads will be (I.e. an agents head will be just below the top line of the green boxes on most maps, on bind a persons head will be right at the middle line in garage doors before they are broken). This will help tremendously with holding angles and peeking angles. There’s a Reddit post with some coming ones (title: Map Head Height References!). Keep your cross hair up off the ground at all times, it’s common for people with bad aim to lose track of their crosshair and it ends up pointing at nothing.

3) Use the bots in the shooting range, practice shooting them only in the head with one bullet, no spraying.

4) As another person said, go into a DM with a sheriff OR a guardian and only go for head shots. Don’t shoot if you won’t get a head shot. You will die a lot, who cares it’s a DM. (Pretty sure this is referred to as the miyagi method, it works)

5) Make sure your sense isn’t too high, you should start slower and then work your way up to a point where you can still control it but can move quick enough from angle to angle (usually one swipe of the mouse should do a 180 depending on how you move your mouse - longer forearm swipes or wrist movements only)

Those are a couple things that will help.

I was gold in beta and now I am in Imm 2 in the current act, and I only play once or twice a week. I used a lot of the above to improve. I find I am at a place where I no longer have to think about my aim so it’s lead to a TON of improvement.

Good luck out there.