I've added an Etude Chart to the Scale Chart on the wall of both my studios, so students can track their progress all the way from Freddy Fiddle (an activity book that I use with my youngest students) to Kreutzer and Rode studies that very advanced students play. And besides, a little - just a little - competition can be really healthy in the studio.
1. Increase the number of days you practice. If you usually practice 4 days a week, practice 5 or 6. If you usually practice 6, practice 7.
2. If you're already practicing 6 or 7 days a week, increase the amount of time you practice. Try adding just 15 or 20 extra minutes a day to your routine and observe your progress!
3. Record your lessons and watch them back as soon as you can afterwards. Buy a notebook just for your violin observations and take notes as you watch your lesson - what did your teacher say that was really helpful, and also, what do you notice about your playing?
4. Record yourself playing at least once a week besides your lesson and watch it, taking notes. Make observations as if you are your own violin teacher and adjust your practice plan accordingly.
5. Set goals for each practice, such as "I am going to play my scale with all the ringing notes in tune" or "I am going to get all the way to the tip on my down bows" or "I am going to focus on keeping my fourth finger curved." Goal-oriented practice is MUCH more productive than randomly playing through things.
6. Don't play through your pieces more than once a day UNLESS you have a performance coming up. Target your practice on those problem spots or focus on improving one aspect of your technique on a small section of the piece before trying to apply it to the whole piece. For example, if you're trying to use a particular bowing, such as a whole bow followed by two half bows (which my students know as Whole Half Half), practice that first on an open string. Then play it on one measure of your piece, and repeat it until you can do it successfully every time. Then play just one phrase, again observing for the bowing. Then add a second phrase, and so on. Once you work through the whole piece one section at a time, THEN and only then go back and play through the piece to see how your work has improved the overall effect.
7. Work on things you aren't good at. Look at your practice chart or your lesson notebook and ask yourself which thing you would really rather avoid when practicing. That's what you should start with (after your warmup).
8. Remember, it's HOW you practice. Be consistent, be focused, and be goal-oriented. And if you don't believe me, here's a video of Pam Frank, a wonderful teacher at the Curtis Institute.