About four years ago, I dashed into a stationery store a few minutes before closing time with a purpose in mind—obtain an A5 Filofax. I had made the decision to use A5 for all my work-related planning and record keeping. I bought a black Finsbury. Not my favorite color or style, but it was all they had, and the rings were nice and big.
I had made a commitment to stop changing systems every few weeks. If I had to change anything, it would only be at six-month intervals. And so I stuck with the A5 for 4 years.
But to be perfectly honest, I never came up with an A5 Filofax system that worked well enough. I ended up writing to-dos in more than one place, sometimes losing them completely. The day-per-page had too much room to write, the month-per-2-pages not enough. I wasn't seeing the information I needed to see when I needed to see it. Even making my own tabs didn't solve these problems.
With an increase in the number of projects I have to juggle at work, the whole system broke down.
My new solution will depend on full-size file folders for to-dos and project info, an online calendar, a basic notebook, and a full-size appointment book. I don't have all of this paraphernalia yet...time for another trip to the stationery store.
But don't worry, I still have 2 other Filofaxes in my life!