As the clocks change in the UK, my brain almost inevitably starts thinking about what diary/planner/system I will use in the following year. I know... it's only the 1st November today, but if I don't think about this soon, I'll get to the end of December and not have thought about it at all.
In the past, I have used a vertical week-on-two-pages diary, and used it for a combination of time-boxing (allocating tasks to time) and general planning, and I do like this system. It's general enough and flexible enough for me. I don't have a gazillion appointments in a day, nor am I far from my desk most days, so there is no need to have something small and portable. Mostly I've used something about A5 sized, and bought a pre-printed diary/planner, but this year, I'm considering trying to 'do my own thing' in an A5 dot-grid notebook. It's not like I don't already have a cupboard full of them!
I would stick with a vertical-day format and have 8 columns running across the double-page spread: 7 for the days of the week, plus one for notes/to do, but I would also have a double-spread in-between, for a weekly plan, plus a weekly review, which is something I've been bad at doing this year. Likewise, I would have monthly (or quarterly) plans and review pages, and hopefully some pages for project planning in there.
That adds up to a reasonable number of pages, but there are plenty of notebooks out there that could cope.
In no particular order, there are 4 great options available from Nero.
Rhodia A5 soft cover. The paper is excellent and there are 160 pages, which would be enough. My only real gripe with the Rhodia notebooks is the ribbon marker, which I feel should be an inch or two longer, but this is a fairly minor issue.
Rhodia Web hardback version, which also has a few more pages (192). I have the same issue with the short ribbon marker.
Regalia A5 notebooks. They have superb paper, 192 pages and 2 ribbon markers.
The Odyssey A5 notebook. This is actually a bit too big for me for a diary/planner, having 496 pages, but for the Bullet Journalers amongst you, it's probably fantastic!
At some point soon, I will have a rummage through my stationery cupboard and decide which of my myriad notebooks to go for. Yes, it might take me an afternoon to create the planner, but I know what I want (and I have stencils!).