They say "said" is an invisible word you can use as often as you need because readers don't notice it. Are there other invisible words? I'm specifically interested in these three, because I'm sick of writing them. It seems like somebody is turning around, turning away, turning to look at, stepping forward, or stepping back at least once every few lines. Should I give up trying to describe every movement my characters make? I feel like I'd lose a lot of depth that way. Whether a character meets or avoids another's eyes at different points during a conversation can speak volumes.

Somebody's probably going to tell me to use more synonyms, but I wonder if there's any other advice people have. Maybe I need a bigger vocabulary, but the synonyms I come up with often don't fit the context. ("Whirl" can't describe somebody turning slowly, for instance, and "rotate" is the wrong style altogether.)

Good question, I never really thought about that too much. I'm sure I do it too.

My advice would be the same advice I give myself on just about every subject:

Open up the books of your favorite authors and see how they deal with it. If you suddenly notice a lot of those kinds of lines, and you never remember noticing them before, then they are invisible. Otherwise, you may learn what they did instead.

That's why I keep over 10,000 ebooks on my laptop at all times. For researching and comparing author styles on little things like this.