Concentrate when practicing.
Concentration is the ability to focus on something without being distracted. It means that you can clear your mind of other thoughts and channel all of your energies in one direction for extended periods of time. Concentration is an important tool for development in any area, and everyone can develop the ability to concentrate. How? Just by trying to concentrate, for for short periods of time and then longer ones. At first you may only be able to focus your energies for thirty seconds or a minute, but if you keep trying, you will soon be able to concentrate for five minutes, ten minutes, then even much longer periods of time.
Sometimes we have so many things going on around us, with video games, music blaring, television on, other people bustling around, that the hardest thing to do is just sit still. We can use our practice time to sit, collect ourselves, and be calm. Then we can develop our mental powers by focusing purely on the task at hand, which is projecting our best personality through an instrument.
Wynton Marsalis, from “Marsalis on Music” p. 127