I saw this post today and wanted to share it:http://music.tutsplus.com/articles/10-essential-principles-for-learning-guitar--audio-6414
I'd like to add a couple of ideas: I often give my students a sheet which I call "Power Practice" It has 6 boxes labeled "2 Minutes" and one box labeled "3 Minutes". In the first 6 boxes we'll write things like "G chord 4 beats C chord 4 beats repeat". All they have to do is the change back and forth between a G and a C chord (hopefully with a metronome) for 2 minutes.
The next box might do the same for a C and F chord. Or a G and D chord. Just fit it to whatever they're doing.
The last 3 minute box is usually dedicated to whatever song they're learning. Now, 15 minutes of practice is not much. But if they can at least do one Power Practice per day they will improve. If they're the kind of student who loves to play then just have them start their practice session with a 15 minute Power Practice. If I have a student which is severely "practice challenged" then I'll spend the first 15 minutes of our 30 minute lesson doing a Power Practice with them. In just 15 minutes they will noticeably improve.
The other tip is a metronome tip. This is for more advanced students. We all know that we should practice with a metronome. But for many tunes it's better to have the metronome click on beats 2 and 4. Certainly if it's a jazz tune that makes it swing better.
But try this: Cut the metronome time in half and have it beat ONLY on the 4th beat. Boy, will you find out quickly just how accurate your time is. I've also found that a couple of students found it easier to work with a metronome that had a blinking light on it as well as the click. When they're playing they may have a problem hearing the metronome when they're concentrating so much on just trying to play. But the blinking light gives then a 2nd sense other than sound to lock in to.