I think feet is a good call but you should also have a good look at your upper body turn when you're prepping to get down on a shot.
I tend to rotate my upper body until it lines up with my shot and put my bridge hand down when I've set my shoulders on that line. Result is that my bridge arm shoulder is pretty much right up against my right cheek (I'm a lefty) leaving no upper body movement anywhere except my cue arm.
You should keep in mind that not everyone cues right through the middle of their chin. This depends on if you have a dominant eye, only those without a dominant eye should be trying to cue right in the middle of their chin. Everyone else will be a hair left or right....sometimes more than a hair.
A picture of your current stance would be very helpful in making some suggestions if you're inclined to post one.