Such a lot of good ideas here! Starting slow and pushing the metronome speed about 5 beats per minute once each week seems to work for many. The hardest part for me is continuing to listen critically to what I'm doing. Each time I speed a tune up, some weakness in my technique causes me to lose it at some point in the tune. Each time I play it, it'll foul up at the same point. If I'm listening well, the recurring mistakes point to problems that need fixing.