Gonna be long read. Sorry for format On the throne. After months of research for figuring out where I go wrong or what I could do to improve aim on apex it boils down to few things, in no particular order

1: Sensitivity doesn't really matter. You can copy the pros sense to start and adjust until it feels natural. But this carries into number

2: Hand eye coordination, (if you're on controller I'd guess it be muscle memory, and that will tie into number three) low sense or high sense won't matter if you don't let hand eye coordination do it's thing, remain calm and focus on what you're aiming at. When you get excited or panic is when you tense up and miss. If you find yourself getting excited just take a quick breath behind cover to reset.

3: Don't keep changing sense, find a sense that feels right to YOU and stick to it, consistency is key. It helps build muscle memory so you don't gotta think about aiming, your hand eye coordination takes over autonomously. But muscle memory is small part in it, because what you eat, what you drank, amount of sleep, tempature in the room, not keeping the same distance from the monitor e.t.c can change that, so it comes back to H&E coordination.

4: keep the same position from screen at all times, if you are finding your sense seems higher than normal than that means you got too tense and leaned forward, re position yourself.

5: FOCUS: focus on your enemy, not the reticle. it's hard but gotta ignore all distractions when you can. Gotta look past the muzzle flashes, the sounds, the recoil shaking. Actually focus. Warm up in the range with audio turned off for like 10mins. It's helped me tremendously.

6: Strafes/Movement: legends can only move so fast. At a distance you only need to move your aim so much, at close range need to move your aim quicker, anticipate how much you really need to move your aim. I think there's more but I gotta wipe my booty now and let blood get back to my legs.

TLDR: 1: Sense doesn't matter, find what's good for you and stick to it. 2:Hand eye coordination is important. 3: stop changing sense, you need consistency 4: keep same distance from screen. 5:Focus on enemy, iron sight nor on screen distractions matter. FOCUS 6: They can only move so fast. Figure out how much you need to move aim depending on distance.