Practice is extremely important for any musician. Instead of practicing less as we get better (as some non-musicians suspect), we actually practice more. Right now I practice four to six hours a day, and that time doesn't set itself aside on my calendar. I have to create it.
That's why you will rarely find me at a meeting or appointment between 10 am and 3 pm (or preferably before 5 pm at all). No one else will protect that time, so it's up to me to leave the bulk of my day free for some of my most important (and definitely most fun) work. Are you guarding the time on your schedule for what needs to get done?