There is a big question about "practicing slow" among students. Here is your answer. You should practice as fast as you can count! Yes, 1-2-3-4-1-2-3-4-1-2-3-4. If you feel like you have to practice a piece slow at first go ahead. Use a metronome if needed and play through the first page or two as slow as it takes. Now speed it up a bit every time you go back through the piece. Maybe five times.
Some parts your going to mess up on, right? Of course. Don't wait to fix those parts. Do it now! Get those parts up-to-tempo so you can play through them. It is probably only a measure or two. Don't think that is hard, find some key notes, make it easy! Think first! Then practice this measure or two five times!
Do not get tense, just feel like you are experiencing and getting to know the music. Counting or singing along really helps you relax.
Eventually you will be able to speed up the process and learn things faster. Of course, you'll hit a road block and have to go back to a slow tempo.
The last key to practice is using the correct fingering. 90% of the notation I put into the score are fingerings, in a Bach piece that has a tricky finger pattern, I'll have to figure out the fingering and write it in! (usually not that hard), then practice it about 10 times while COUNTING. If you are not counting the rhythm or singing the tune out loud, you are wasting your time just going over the notes again, and again, and again, and again. The "beat" is the framework for understanding and building motor-memorization.
Practice smarter, not harder. Have a plan and learn that piece of music!
