- Be aware of your surroundings. You never know when someone might flank you. - Be aware of the objective. Control points, payload, capture the flag. Know what the mission is and don't just run around killing people. I hate sometimes when we're playing a King of the Hill map and we lose because everyone's too busy killing off on the sidelines and not pushing point (this includes myself). - Be aware of your teammates. Scouts and Spies can get away most often with running behind enemy lines, and Snipers and Engies are great at staying back, but you want to be with your teammates most of the time instead of straying out too far solo. Don't glue yourself to your teammates, but don't just be Leeroy Jenkins. Also, awareness of your teammates can help with catching spies.
*shakes fervently*
Who are you?! ---
"In my headcanon, some staffer saw Trump pull out his phone and start typing so they just Terry Tate Office Linebacker'd him out of his shoes." - FFD