Basically, in order for combat to work the two players need to comunicate. I can't stress that enough. IM is the best thing to do, PMs and emails are also good. If your messages are not being answered, contact a moderator.
It is also a good idea to work out the battles before hand. Know who you want to win or lose and know the terms for winning or losing. If neither of you wants to lose, then lower the risk in the fight (from death to unconciousness, maybe) or bring a moderator in to make sure that everything goes smoothly.
Remember that you can never auto another person. That is to say that you cannot post what they think, feel, or do and you cannot post that they get hit or that they get hurt. Here is an example of what NOT to do:
He shot the blaster with near perfect aim. The winds were still and the blaster bolt flew true: it hit his opponent in the heart. Rushing over, he delivered the final blow upon his enemy with his dagger, once more to the heart.
Here is what TO do.
He shot the blaster with near perfect aim. The winds were still and the blaster bolt flew true. He waited to see where it hit, ready to rush forth and attack at any moment.
He saw the blaster being nocked and rolled to the side just as the trigger was pulled. The projectile grazed his shoulder breaking the thin armor and scraping the flesh. He cursed under his breath and charged forward with his blade, trying to hit the soldier before he could shoot again.
Infallible Character Syndrome.
This applies to the defender, who gets to choose whether or not they get hit. All too often, I see people who somehow manage to evade dodge, or block whatever is thrown at them. People get hurt in combat. They muck up in the heat of the moment. That's just how it goes.
Here is an example of what NOT to do:
Ducking under the Sith's swipe, he did a backroll right as the Soldiers blaster bolts struck the area he occupied. Arising unscathed, He put all his might into his shield arm to block the Sith's swinging lightsaber.
I'm not saying that one should assume they get hit, but really consider whether or not they could defend against the attacks presented. It is all too easy to think of the smart thing to do in a situation, but take a moment to think if your character would really be able to concieve it at a moment's notice.
Plus, there's a certain satisfaction in describing the wounds inflicted.