As I was walking around, I heard a violinist playing these wild exercises-he was wailing! I thought it would be really cool to adapt those licks to the guitar. Since the violinist didn't speak any English, I had to gesture for him to show me what he was doing. He gladly did, and then he showed me a bunch of variations, too. It was great; though we didn't speak, we nonetheless communicated very easily.
Dream Theater's John Petrucci helps you better manage your time in part one of his series of practice tips. "Of all the things that can frustrate a guitarist the most, it's the nagging feeling that he's not reaching a certain level of proficiency as quickly as he should."