the only system that works for me is having one big calendar in a prominent place at home and a small calendar I carry with me.
For the big calendar, I use a Poketo Spectrum Wall Planner. That’s to keep track of bills, social events, & travel plans.
My small calendar is a Hobonichi Techo Planner for smaller tasks, reminders, and lists.
when I’m good about using them, I actually show up to things & I’d recommend that!