Many artists will tell you ... from time to time they hit a wall. The come to that place in their own minds that starts to sow seeds of doubt and despair. A dark angry place that often times causes most artists to tear down pictures, throw their brushes and call it quits to the whole damn thing. They don't really want to quit, many of them can't quit, but they're just so frustrated that their work isn't progressing as fast as they want, or they feel like they're stuck in a rut.
It's times like that they need to change things up. Grab something they've never used before and try something they've never done before. Get messy, get weird and above all make it fun again.