I'm still doing this after starting a year ago. I've filled up one large ruled Moleskine and am 50 pages into the second one. I have calendar pages where I don't do any forward planning, but just write a one-line summary of what I worked on that day. Empty lines or variants of "slacking off" are an instant sign of trouble.
Other than that, the nice thing is just that I have a designated single nice journal to do any sort of brainstorming notes I need. Random ideas, planning an ongoing project or reading notes all just start by labeling a new page on the journal and writing down whatever is relevant.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.