Every day for a large portion of the day. I use an org-capture template which lets me capture tasks and I keep all my notes in those tasks including proof-of-concept code, etc. I capture and schedule meetings through the same template which pre-populates things like space for a list of attendees, the agenda, after-meeting notes, and action items which become todos. I even track the amount of time I spend on each so I can fill out my timesheet as I'm in a field where we maintain billable work, etc.<p>All this to say it's a very flexible system and lends itself well to keeping notes.
Yes, I have a little template that I update every day with what I've worked upon.<p>There's a simplified version available here, with two shortcuts `M-x new-day` to create a new (templated) entry, and `M-x today` to jump to today's entry:<p><a href="https://github.com/skx/org-worklog" rel="nofollow">https://github.com/skx/org-worklog</a><p>What I use is a little more complex than that, but this might be a good starting point for the curious.