Here's a thoughtful blog post on the subject of practicing by my friend and colleague Eric Miller. If you have a moment, please follow the link and read the whole thing.
"In college, I was always in awe when I went to a percussion
student's recital. The recitals, unlike those of string players and wind
players, were always perfectly executed; not a single mistake. I also
noticed the pieces were usually memorized. In order to get to the bottom
of it, I read a book by a percussionist named Steven Schick called The Percussionist's Art.
In the book, Schick, who is an outstanding performer, outlined his
practicing process. He memorizes the first note, then the next, always
returning to the beginning and playing through, adding notes each time."