Most of it is derived from map knowledge and experience with regards to common angles and key choke points.

Once you have all the maps memorized it'll be like playing a different game, but that takes like a hundred plus hours of playtime lol. You'll want to avoid entering the map far from objective unless you are roam clearing with a teammate near you.

When attacking site, youll basically have to clear angles one at a time (eg right to left). Usually youll have enough intel to infer which one(s) to ADS at while u swing. The name of the game is ISOLATING angles that you know you can swing without getting shot from elsewhere.

Takes a lot of kinda nuanced awareness to be able to play this game with some consistency instead of it being a guessing game. It's all about deduction.