Budgeting my time
As a freelancer - with an active creative mind - I can always find things that will get in the way of doing the work I need to get done.
After years of attempting to accomplish everything for everyone (yep, I'm a people pleaser), working evenings, weekends and holidays, I finally got smart with my time. With careful planning, I now separate my work hours from my play time.
When I book a new project, my formal proposals have milestones built into the project. When a change or revision comes in, I will turn it around within 3 business days (that is, unless something dramatic has occurred.) Surprisingly, sticking to a traditional Monday - Friday, 9 - 5 work week has made me more productive, not less.