Runners World has a terrific article up on "GPS Rules". This hits home for me since I've taken to being far too reliant on the watch in times past. When it broke, I was able to break the cycle of always needing immediate digital feedback and have been far better off because of it.
RULE NO. 1: DON'T LOOK Don't look at your GPS for the first 10 minutes of your run. GPS users often start their runs too fast because they let the watch set the pace instead of letting their body settle into it. Listen to your body. Let the pace come to you. Don't force it on yourself early in the run just because the watch says so. And, even when you do take that first peek at your watch, don't surge to hit your intended pace. Flow into your normal pace over the next mile or two. Trust me. You'll feel the better for it.