I keep a physical daily journal in an A5 Dot Grid book. At the end of each day I draw a template for the next day and try to fill in as much as possible. For example: on January 18, I drew this for the 19th.
The red checklist at the top is three things that I must get done that day (The Big 3). This is reserved for my most important tasks. If I can’t commit to three, it’s ok, I can use one or two, but never more than three.
Then, below that are my time blocks for the morning and work-day. If I have meetings, I’ll put them in, and then I try to find a couple of big blocks to work on my Big 3. It’s ok for this to be a little blank the night before, but sometime in the morning it will be mostly filled in.
Under that I’ll keep a running list of tasks and notes for the day as a bullet journal.
This technique is a result of refinement over time derived from a combination of Free to Focus and Deep Work, both highly recommended.
I have a variant of this that I do at the end of the week that I’ll post about soon. One element of the weekly plan is to collect my WINS from the week before, so at the end of each day, I try to pick out one or two things I did that will bring me joy later when I reflect on them.