I do like the WH Smith 1 day per page format. It's not structured so I can write notes as I wish which suits me. I tend to have lots of "To Do" items and not many appointments.
I do use the appointments to carry out a particular task as at a set time but my job is pretty hectic and the best laid plans often go out the window!
Here is the WH Smith 1DPP format:
Blank 1PPD Diary
Here's what it looks like after I've been using it!
I use the fantastic Frixon pens - red for urgent, blue for normal and cyan for personal stiff. Green highlighted means completed and yellow means in progress (I've started and hopefully will finish!!)
The (N) after a task indicates there is a note in my organiser to look at. (RMK) or (DWA) after a task indicates the initials of a person I need to discuss that task with.
The main issue is the paper quality - it's not good! I do prefer Filofax paper so I'm thinking of making up a template (when I have time) to print my own.