Practice does not make perfect.
Practice is an ongoing commitment to yourself, and ongoing support of your own decisions. It's what you do every day. If you swim every day, you become a swimmer. If you write every day, you become a writer.
In a very real way, practice is your main tool for co-creating your life. It puts you in touch with the magic inherent in the physical world, because you are making things happen. You're participating in your own evolution. How cool is that!
Mastery is just another level of practice. You're not practicing until you reach some arbitrary level of "good enough." You're practicing so that you can keep practicing, and keep connecting with that spark of creation. That's what we're all working towards, no matter our type of work.