Limit your daily tasks to three areas of study, for example: Reading, Technique, and Repertoire (tunes). It is an easy mistake to spread yourself too thin. This results in poor quality. Set 30-day goals with a qualitative requirement attached to each goal. It is not productive to have worked on ten songs, if when you perform them, they do not sound great. An easy measure of how well you should know a song before moving on is to simply answer the question: Am I excited about performing this for my friends? If you have to make excuses--it is not ready. If you decide that at this time there is no way you can master a particular piece, choose a more simple song. This is not failure. This is smart practice.