Don't hog the desk
In the past I've written about how important it is to be a considerate driver (typist) while you have control of the keyboard, and how navigators can become better communicators. What else can you do to improve your pairing?
Play nice, share the desk
If you take a look around most agile development shops you'll normally find a couple of pairs where one of the developers has a significantly better view of the screen than the other. It's often the developer whose computer they're using, but sometimes it's simply whoever happens to be typing.
It's a recipe for disaster. If the navigator is sat just out of the driver's field of view the driver will be less inclined to pause and discuss their plan with the navigator. If a navigator feels uninvolved they become less inclined to interrupt the driver and eventually lose interest in the code.
Switching regularly between driving and navigating helps to keep both programmers involved, but it isn't the whole story.
Drivers who don't notice when they're hogging the computer often don't relinquish the position when their partner takes control of the keyboard. This is a great way to annoy your partner.
You have to position yourselves an equal distance from the middle of the screen.
So when this happens to you, what do you do?
Chat about it with your pair. It's easiest to do it at the beginning of a pairing session, rather than when the problem arises during coding. I usually suggest (to people new to pairing) that we imagine a line down the middle of the desk, and that neither of us should feel the need to cross it. It's then easy to remind each other without making a big deal of it. Mentioning the line once or twice solves the problem.
This goes without saying these days, but you should also get each member of a pair their own mouse and keyboard. If you have to keep pushing the keyboard around you're asking for trouble; it's more natural to slide yourself sideways into "pole position" than it is to drag the keyboard towards you, away from the screen. It doesn't stop some people from shuffling their chair towards the monitor, but it helps!