It sounds like common sense, but keep in mind — you’re controlling a character that, in some ways, moves like a tank. Strafing, moving, aiming, firing, and trying to do all of these things at once is not easy on a mobile device, and it gets significantly harder when most of the zones have closed and you’re down to the last dozen or so players.
Run away and heal up whenever you can. This is fairly good advice at almost any stage in the game, but it becomes absolutely imperative to maintain an edge near the end because it’s not a mere possibility but a high probability that there are other players close by that can hear your firefight. Try to disengage as quickly as possible if you can’t get a quick 1v1 kill, because whoever’s watching you will have the upper hand at aiming if they’re standing still