To me, a sure-fire way to get in a rut is by sitting around playing by yourself for too long. You've gotta get out there and jam, man! You don't have to necessarily be in a band, all you've gotta have are a couple of buds who play too. They don't have to be guitarists either; jamming with a bassist or a drummer is cool.
Dimebag Darrell
Man, Yourself, Me 