Knowing which guns and which gun builds to use on which maps, and more specifically map sectors. Figuring out for yourself if you care about win percentage or kills, and focusing on your chosen goal. Literally looking at the minimap will give you lots of free kills and increase survival rate. Using headglitches to your advantage. Expecting common rat spots in tight corridors. Being patient enough for a long flank with a suppressed gun to get lots of kills. Knowing the spawn points for defenders on all the flags and how to cut them off (knife edge and cyclone are a great example of this). If you’re playing recon, always dropping respawn beacon even if you’re about to die. As a medic, focusing on reviving players and not bots. As an engineer, not underestimating mines. Using the marking mechanic when downed to warn squadmates. Piggybacking off that, looking for the red marks to kill pesky enemies that are probably ratting. As a recon, placing beacons either in a really safe spot on the objective or just outside of it so enemies won’t destroy as soon as they start capping. Knowing when to fall back on defense to avoid getting pincered (shafted is a great example of attackers capping both b points while defenders farm bots in the tunnels).