Don’t. Of all the selfish crap you can do. What is with this idea that you have to win in order to have fun. If you are in a team game, do not quit. Every minute you survive is another minute your ally only has 1 enemy to fight instead of 2 and a chance for him to save you. If you can’t handle this level of respect for fellow gamers, don’t join team games.
If you’re in a 1v1 fine, quit, I think this is lame also that folks don’t see this as an oprotunity to look around and enjoy the scenery as the remainder of your fleet is destroyed, or strike up a conversation with the like minded gamer you just battled to discuss the battle you just had and learn from it. But whatever.