How is the best way to practice?
This is an excellent question with no simple answer. As a student, you may be just beginning. Or you may be an advancing student who has been playing for many years. Professionals and great artists, of course, also practice. And types of practice are going to be dependent on what stage, level of development, level of commitment, ability your have attained in addition to the style/school you have learned.
I could suggest certain methods of practice, and many might agree while others might disagree with. To generalize, I think it is safe to say that there is no one way to practice, nor is there one style which is the best (although some are better than others!).
When speaking for students, I would say that there is one constant which can help regardless of level/style/school: Routine. Think of all of the routines we have in our lives. Most of us go to sleep at night and wake up in the morning. We expect the sun to rise in the east and set in the west (and we are never disappointed!). School usually occurs during the week, etc. We as humans are quite used to routines, and these routines seem to suit us pretty well.
What constitutes a practice routine? What you practice, how long you practice it, and how you practice should all be what is in your practice routine. Hopefully this will include the suggestions of your teacher, orchestra conductor, etc. And you can experiment with your practice routine, tweak it, perfect it, and change it again and again until it is just right for you at this specific time. Then, of course, you will grow and change. And your practice routine, hopefully, will evolve with you!
Once your routine is established, practice can become a consistent part of your life!