This.
Simply put use your killing power to ... um, kill people, and don't get caught into chasing people in the open or archers when there's still other people that you can kill. Heck, if you are chasing someone for a longer time while the battle is still going you are doing it wrong in the first place, especially if you are outnumbered just let him run away and try to backstab the guys that attack your teammates.
Well, sometimes you are stuck in a situation where you don't know what else to do, or have to hide from archers, just deal with it, the amount of kills you can make before you run into such a situation is pretty much worth it.
If I knew there'd be a lot of roofcampers I'd just take 2 ladders myself. This slows you down quite considerably, but then someone can reach them easily.
Of course if I'm archer myself I sometimes love to make sure that melee people see me. Half of them totally forget that there's an axeman swinging at them if they see some 1 hit kill target who can't block ... almost ... in ... their ... reach ... *slash*