It's not how long you practice, it's the quality of your practice. As soon as you get home from school, set up your machine. If you find that you have five minutes of free time, pop in a speedbuilding tape. Focus your attention to one area, whether it is concentration, speed, or accuracy, and try hard to achieve that specific goal. That devotion to only five minutes of hard practice and concentration will benefit you more than one, two, or three hours of half-hearted practice.
Use realtime. Realtime is your friend! It will help you build your dictionary, see your mistakes quickly, and become a more accurate writer. You will soon begin to find it much easier to read back from your computer screen than your notes.
Vary your practice. You don't always have to focus your attention on speedbuilding. Vary your practice routine by listening to material several speeds below your current level. During that practice concentrate completely on accuracy, stroking the words correctly, and using briefs for common words and phrases.
Keep a new briefs notebook. Begin to devise a notebook full of common briefs and phrases. If you hear a word you don't know how to write, put it in your notebook and work out a stroke for it. Keep your notebook in front of you during practice so that the next time you hear that word or common phrase, it won't be unfamiliar anymore.