I honestly dont check anything other than the amount of fuel before I ride out... but that's not a clever thing, it's just laziness Haha
I check the tyre pressure every few months (when I remember) and other than that I check things when they stop working.
As for regular 'maintenance' I'll wash it every fortnight or so depending on use, oil the chain everytime I wash it.
I change the oil twice a year (before and after winter months), clean the air filter every 6 months or so.
Once a year I'll take the calipers off, check the pads and while I'm there clean and regrease all the pistons, I undo all my exhaust studs and reapply copper slip, decrud/clean the lower suspension linkages and apply ACF50
That's about it really
With the current lockdown in effect I've recently stripped all extra parts off and given her a 'super deep clean' which has gove me chance to do some of the other random little maintenance tasks (like changing the rear caliper fluid) and has helped me spot a few bits that need doing