Don't allow yourself to become easily distracted. Distractions cause you to start over. They also can make you feel frustrated. If during your practice time it is getting difficult to focus on your goals, stop and come back to them later. That will help you to make the most out of your practice time.
Most people your age really love video games. Have you ever been so involved in a game that you lost track of time? It could feel like you have only been playing for a little while when really it could have been several hours. That is because you were so focused on the game nothing distracted you. You were totally concentrating on the game.
Good concentration during practice will only help you to be more effective in your work.