Play to your strengths, not what you think you should do. If you're not a natural assaulter, don't go for cqb and fast pace twitch-reaction combat, if you don't have good detail perception, don't go for sniping. If you want to be effective beyond your limitations, play in manners where your limitations are not even a factor. For instance, anti-vehicle and combat engineer repairing vehicles, or medic or backlines support with ammo and defensive gadgets, even fire support with mortar, or even being an actual reconnaissance spec ops recon with SOFLAM etc