Most successful scheduling system to-date:
I divided each day up into four chunks:
  • Morning (10-12),
  • Early Afternoon (12-3),
  • Late Afternoon (3-6), and
  • Evening (6-9).
Then I put tasks into one of three categories:
  • Small,
  • Medium, and
  • Large,
where there are
  • several (~4-5) Small tasks to a Medium,
  • two Mediums to a Large, and
  • only one Large task fits in one of the ~3-hour time-slots.
Take a break after every significant thing.