I have a stack of about 30 Moleskine notebooks I've gone through over the past 10 years. I mostly work at the computer, so I keep the notebook open in front of me while I work and I usually wind up creating a checklist each day of what I intend to do, then use the pages to draw out ideas or sketch thoughts. Sometimes I find myself writing something to try to remember it. I try to look at the previous day for continuity but otherwise rarely need to look back. I also use it for meeting notes.

I put a unique sticker on the front of each one so I can sort of associate the time / topics with the notebook. Otherwise they all look identical.

It's not really that organized, but it helps me keep focused on tasks each day and sketch out ideas.