Hi Paul,
I have the following tabs in my personal size filofax:
  • Notes/In
  • MITs - most important tasks from Zen Habits in my Dodo Pad
  • Action lists - one sheet of paper for each context
  • Projects/goals - just a list of what they are
  • Project plans - more detail
  • Ref/misc - notes, workflow diagram, weekly review sheet etc.

I think if I had a lot more next actions, I might consider tabs for them.