How I write fight scenes.
Use A Map. Sketch out your props and your characters. This is useful not only with large rooms but small ones as well. Is your character on the run? You need to know the obstacle course.
Focus on one POV character at a time. I write in layers so it helps me to first map out the scene, and then focus on one POV at a time (if you have multiple POV’s) and begin to layer.
Time it. How long does it take for bad guy to reach good guy? What is good guy’s initial reaction? How long does it take for the contact? I actually time a scene visualizing it with a stop watch. Yeah, I’m just weird that way. So when I write I know how long the scene is going to take, how much time does the POV character have to think? Now, you can argue that time is relative in stories. Linear time in a story doesn’t exist like real time. Think Inception. Time is what the author gives the character. But you want to make it as close to reality as possible.
Act it out: This one is a bit tricky but can be fun. The objective of this is to get a feel for the movement. Your character may have super powers, may know how to handle a sword, a gun, a blade, but feeling the toll it takes on the body and the mind might give you a baseline. And you can begin layering from there.
I had my teenage, petite, girl character, swinging a sword. Yeah, well have you ever carried one? Those things are heavy. Definitely needs upper body strength. Archery? Back and arm strength needed there. This will help when describing my characters and giving them daily chores. And gun wielding, careful with that recoil. You can find hilarious mishaps on youtube.