One possibility.. if you can't visualize, you might try posing yourself, to feel the sort of movements you're looking for. In other words, while you've gotten others to choreograph in front of you, why not be one of the actors now and then, so you can understand (for example) a character's inner flow as they move through the action, and can then describe that for the reader?

I also suspect that as you learn the choreography, you'll get in better touch with your body and visualization skills.