I've got an interesting idea that probably at least some newer players/students don't think of. Actually it's not something I hear a lot of teachers recommending. RECORDING your playing, even if it's just practicing. Obviously, if you are a very beginner, there may not be a big advantage in recording yourself. However, I have learned from personal experience that recording your playing later in your progress, can be very beneficial.
I can't recall from whom I got the idea, but it has opened up another aspect to my playing. Now I understand that at some point most people start recording, but I'm not talking about just making demos, or recording a 'finished' tune. I'm talking about listening, really listening to your progress.