I think one of those most important things you can do during a practice session is to set a goal. In my opinion if you're not setting a goal you're not really practicing. But what does that mean? We all want to play better and sure that's a goal, but when practicing we need to be very specific about our goals. If your practice sessions consist of unfocused noodling or replaying of songs you've known for a long time, try something different. Maybe this...
- Narrow your focus
When goal setting you need to be very specific. Not just, "I want to play better." or "I want to play this song." Its better to say "I need to work on this particular passage of this song." And then stick to just that small section of song until you've improved it. Maybe you have trouble with pull-offs. Well spend your practice just working on pull offs or at least focusing on getting them right.
Maybe, you play a song pretty good but always mess at this one part in the middle. Narrow your focus to that part and figure out how to play it as smooth as you can. ONLY THAT PART. Practice only that part until you improve it.
Narrowing your focus can be like a microscope you hold over your playing. How narrow you focus it will depend on what you are working on. It can be wide and cover a large section of song or you can focus it down to just a couple notes played over and over.
- Start small
Again, how small is dictated by how easy the piece is for you. Difficult pieces take LOTS of work. Don't try to force the music into your fingers. It won't work. Be realistic. How much time do you practice a week? How hard is the piece you're working on? The harder the piece, the more work you need to put in.
- Go after your weaknesses
- Set goals every practice
It may help to keep a journal of log of your practice routine. This will help you keep track of what you've been working on and help you chart your progress. It will also help you organize and focus your practices.
- Be realistic
If you hope to play an instrument really well it would be wise to consider what the masters put themselves through to play really well. Clearly it helps your playing to play tons. However, I can assure you that an hour a day of focused goal oriented practice will improve your playing. If you've only got ten minutes use it.
Set a goal. I hope that helps.