As one who prefers not to use attributions, I had a tendency to overuse action beats to delineate speakers, often groping for a variety of beats to use, when many were unnecessary and intrusive. These dead beats often proved to wreck the rhythm of my writing.
Yet, well-placed action beats, often called descriptive beats, can heighten the story, give your characters character, when used as reactions to dialogue to show movement or emotions. Reading your scenes aloud should show natural pauses which would benefit from beats or reveal where beats you have used are intrusive and interrupt the flow of the story.
Beats like a raised eyebrow or a quivering hand can ground your character. However, having him raise an eyebrow or have his hand quiver for no reason other than as a substitute for a dialogue tag is a dead beat that does not move your story forward and hinders the rhythm. In a recent editing experience, I encountered the following: “How dare you speak to me in that manner?” She set her cup on the table. “Get out of my house.”
It appeared that the beat was merely an attempt to avoid an attribution and it mitigated the emotional effect of the scene. The first revision simply omitted the beat: “How dare you speak to me in that manner? Get out of my house.” This implied a controlled, seething anger which did not fit the character, and, when read aloud, showed a pause.
The result: “How dare you speak to me in that manner?” She slammed her cup on the table, sending shards of china skittering across the floor. “Get out of my house.” Here the emotional impact is heightened with a solid visual image that displays her anger.
Although solid beats add life to your story, dead beats serve to lessen the emotional impact and rhythm of your writing. So watch for dead beats and remove or revise where necessary.