Actor training gave me a greater appreciation for stage picture than I'd had before, not just for the visual composition and balance of actors on a stage, but to how individual actors sharpen or smear the focus of the stage picture through their individual physical choices and habits. Increasingly, I find myself disappointed by actors who don't match their actions to their words. They fidget, take little random half steps, do miniature undulations of their torsos, waggle their heads minutely, tap their fingers, hold their hands stiffly, et. al. In realistic productions with a naturalistic aesthetic actors often seem to assume that random physical movement certifies the authenticity of their feeling, though what they forget is that we're interested in hearing the story rather than in witnessing actors feel. I almost always feel uncomfortable with 'unnatural' stillness when I'm first on stage--especially in auditions and in early rehearsals--and one of the goals of my own rehearsal process is gently to strip away the unchosen gestures and tics that obscure the story I'm telling. Unchosen movement is an "energy leak," a phrase I picked up from someone (don't remember who) years ago. It's only purpose is to distract myself from the terror of being on stage. Actors need to realize that 'Realism' is not everyday 'realness.' It's a style like any other that calls on artificial technique to create an emotional truth. "Behaving naturally in an unnatural situation" requires the use of a few 'unnatural' skills, such as standing still with hands at easy rest or listening to a scene partner without even minutely fidgeting.
Smearing the focus of one's performance through unchosen movement is typically a newbie issue, but I do see it in professional productions. Even the wonderful and skilled Patrick Stewart smears focus; e.g., watch the RSC's t.v. production of HAMLET (available on iTunes) and you can see a little half step and thing he does with his hands that he's been doing at least since Startrek TNG.
A wonderful place in which to see action match word is in musicals. Those performers get it. The rest of us train in Viewpoints and Suzuki and use rehearsal well.