I have the following tabs in my personal size filofax:
- 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.