Good actions scenes can be tricky. You want to show enough of the action to give a vivid image, but not get bogged down in description.
To start with, you want to have the whole scene mapped out, as if you were doing a story board for a movie. Write the action out onto index cards — or use Scrivener — and arrange them in order so that you can see how it’s going to play out. If you have any artistic talent (or even if you don’t), you might also try drawing the action on one side of the cards, just like a story board. The idea is to be able to visualize the scene completely.
Once you have the entire sequence of action plotted out, and can see everything inside your head, you can start writing. Start right at the beginning of the action sequence. Keep your sentences short and tense. Give just enough description to set the stage, but then go straight into the action.
Another thing to include is emotion. You want the readers to see how the characters are feeling during the action scene. Add in the character’s emotional reaction to whatever just happened. Show their feelings in response to what’s going on around them. This not only makes the characters more real, but it also adds tension to the action.
Following these guidelines will result in tighter, more tense action scenes. Give it a shot yourself.