Only the typist touches the hardware
Breaking old habits of having to touch hardware to solve your problem can be tough. If you are not the typist keep your hands off the keyboard and the mouse. To many things going on at once helps create chaos. You moving the mouse while someone is trying to type is too many things. Look at getting your setup right, typically mobs have a large screen(s) or projector against a wall - if you need to bring attention to something on the screen, stand by the screen and indicate against it using your hangs than grabbing the mouse and moving the cursor. Turning absolute line numbers on your editor makes it easier to navigate the screen real estate.
Stay engaged
Strong mobbing keeps you engaged - I’ve written about this before, for an example of why a mob doesn’t stay engaged read my post on “Staying engaged while mobbing.
Tackle one idea at a time
Different people may have different ideas on how to solve or implement something. That’s a good thing and one of the reasons why mob programming is so effective. Be aware of the level of conflict in the mob. Too
Dominating Navigator
When you’re mob programming with the same navigator the whole time