Personal: Google. I just dump everything in as an event, no real organization. Really useful to remind me to do things like swap out batteries, filters, car and home maintenance, doctor appointments, etc.

Work: I put everything in the Outlook calendar except for time off, which goes into Teams. Hate them both. If it’s just a dumb little reminder thing, I make sure it’s marked as both private and not busy. I’m sure my boss can see it anyway, but I don’t want to make it look like I’m blocking off my availability for no good reason.

Holidays: I refer to whichever dumb calendar is already open.

I sometimes still write things on a nearby notepad or even put post-its on my monitor. They don’t stay there for very long, but sometimes it’s nice to have a physical / tactile element in play.