I always keep a log, though it's rudimentary compared to my big ship and sailing days and the events of the day are usually filled in at the end of the day's passage. I record times of departure, significant features on the way and arrival times. Fuel, distance, speed, crew, etc. too.
Also every new relevant weather forecast broadcast from the Coastguard.
I know my usual cruising grounds very well. However, before departure each day I note departure point and intended destination, tide times, weather forecast, and make a note of my general intentions. In unfamiliar waters I go into more detail. This counts as a 'passage plan' which, I understand, is required for anyone
going to sea, not just the professionals. Should anything untoward happen during your trip, the passage plan will help put you in good light with any involved authorities. (I hope)