When I was in 4th grade I started playing saxophone in the school band. To get an "A" for practicing we needed to practice 125 minutes per week. I never let myself practice less than 130 minutes per week, just so I would always have done better than the maximum time required required.
What does this mean? Probably that I was kind of an over achieving little kid, but more importantly it's a habit that seems kind of dorky when I look back on it, but it really was a good good for me. At the time I was a pretty good sax player (for a 4th grader). As I got older I lost that discipline and ended up being somewhat mediocre at a lot of things that I really cared about.
Recently Eileen and I have been keeping a "Good Habits List", basically a chart of things we should be doing regularly to be better people. I've been using mine to make sure I do things like practice piano and guitar, work out, read difficult, but interesting books, draw, and study. The practicing music has been especially rewarding.
It's not that I haven't been playing guitar (or piano) in the past, but it's been a while since I've regularly PRACTICED either. I spent a lot of time either playing with the band, which was awesome or just noodling around while my brain was often thinking about something else. I've really been working on taking at least 30 minutes several times a week to really focus all my attention on what I'm playing. This means working on technique by running scales with a metronome, making sure I can play chords in any key cleanly, and slowing my playing down so that I don't just brush over sloppiness, but go back and fix it. This also means playing music by other people. I bought some Ben Folds Five sheet music and I've been working through song in that, breaking down hard parts into small chunks and working them out, playing single measure over and over until I can play them in the context of the full song, and then playing along with the song to work on dynamics and feel in my performance. I've been doing the same with guitar; conscious technical work and then learning songs and playing along with records.
These are things I should have been doing for a long time, but somehow I just got out of the habit and my playing has suffered because of it. I'm not putting in 8 hour practice sessions like a concert pianist, but reasonable sized chunks where I'm just focusing on playing better. Since I don't have a band any more and I my schedule is a lot more flexible this is a great time to really get myself into a good practice routine and build up my guitar and piano chops.
It feels like it's already paying off a bit. I've been able to see big progress in my piano playing and I'm remembering how fun it is to play along with songs on guitar. My fingers just feel more at home on the instruments. I've spent a lot of time in the past wishing that I was a better musician because I enjoy playing so much, it feels really good to be doing something about it.