Action scenes constitute payoffs in a lot of genre titles. They can either resolve a longstanding tension in the plot or throw a new element into the story altogether (i.e. the death of a character). And like any other type of scene, there are certain tricks to help make action segments work for the benefit of the book.
The first and probably most important thing an author should do regarding a major action scene is to earn it. Action is great, but it has very little emotional impact without a buildup of drama and potential consequences before the fact. Prolonging the suspense allows the high emotions of the characters involved to feel more genuine, and the reader should consequently be far more invested in what’s going on. A good rule of thumb to keep in mind is the bigger/more important the scene, the bigger the buildup should be.
Second, the action needs a point. No, this doesn’t mean that every bit of action has to be a crisis, but it should still serve the story. This can be anything from establishing character in a short scene to furthering the plot. But if the writer is going for a life or death struggle, the consequences should reflect the seriousness of that conflict. Rarely does anyone get away cheap from such a situation, and a reader will more than likely call bullshit should a character manage to do so without an excellent reason.
Third, the writing should be brisk and descriptive. While the former may be a matter of opinion, it’s a longstanding tradition to approach action with terse sentences. Doing so allows the reader’s eye to quickly move through what’s happening on the page, improving the scene’s sense of urgency. However short lines are no excuse for boring writing. Action should always be vivid. Blood should spray from bullet wounds and ears should ring when someone is struck on the side of the head. These scenes are perfect for a colorful turn of phrase, so take the opportunity to sell them as strongly as possible and make them pop in the reader’s head.
So, while there is no one way to write action, these simple guidelines should provide a solid foundation on which to build. And remember, just as a fistfight, gunfight, or an encounter with some creature from beyond would sure as hell stick in your mind, you need to make sure it does the same for those reading your work.