Steve Streeting [1], if anyone, should know how to plan his work week. He's been at the helm of OGRE (the open graphic rendering engine) and a prolific freelance developer for a qurter century. Refreshingly, he admits that it isn't that easy... even with so much experience under your belt. Check out his post for valuable work tips on how to make the most of your time.
Go read it here. [2]
Links:
[1] http://www.stevestreeting.com/
[2] http://www.stevestreeting.com/2010/09/04/work-2-0/