IWIN button - perfect description!
http://wiki.guildwars2.com/wiki/Head_Shot
The trick is to learn to recognize the skill animations and sounds for the "dangerous" moves, and have a plan for disabling, evading, absorbing, or simply getting away. Frenzy, Quickness, Haste, Lightning Reflexes... there's other dangerous moves, but those ones are all basically "DOUBLE DAMAGE DEAL WITH IT!" moves.
I typically run Dagger/Dagger just on principle, but I firmly believe that Dagger/Pistol will be the most effective skirmish/1v1 weapon set. Then again, I don't believe you're a Thief, so this specific advice may not be useful... I'm positive you do have a Daze, Stun, Launch, Knockdown, Pull, Block... or something similar... somewhere!