I'm pretty bad at making fighting scenes, so I'll put my advice as a reader primarily.
1) Don't make them too long, it gets boring after a while, especially if there is no plot progression during the fight... If I had to wait for a whole month to see your fight end, chances are, I'll be bored.
2) Make them easy to understand. Some people know a lot about fighting techniques and want to show off the intricacies and details of their knowledge... That's all fine and dandy, but if you aren't clear in showing how those techniques apply to the battle, it will basically read as technobabble.
Like... If you start describing how a character set his sword in the high noon stance, while the opponent then set his own in the low moon stance, and after they got closer, he used a full moon swing to incapacitate the opponent's defense due to the inherent weakness of the low moon stance... I'll skim through the paragraph without taking anything that you said into account, because I don't understand a thing that was just said.
So keep things understandable. It doesn't necessarily needs to be simple, but you need to make it in a way a reader that doesn't know a thing about fighting can enjoy what you're writing.
