One thing I learned a few years back was to make every pass count.
Despite having every intention of practicing with purpose sometimes you get in the boat with your buddies, get to gabbing while you put on your gear and jump in. Next thing you know you're in the course and skiing with no plan.
Have a plan and execute it from the start. You may decide to change it on the fly, but have a plan.
Mindless skiing is essentially worthless if your goal is to progress.