With the turning of the calendar, I remind myself that once a year I should clean and tune my tools (table saw, jointer, planer, bandsaw). I usually turn my TS over and partially disassemble it to get out all the accumulated grime and dirty grease on the worm gears, then re-lube it, reassemble it, and take the time to get it tuned as well as I can. Same for jointer/planer knives. All the enclosed cabinet bases get opened and vacuumed.
In other words, it's time for all those "once in a while" tasks.