From Eitan Burcat
- Write all the things that have to happen in a specific date and time.
- Write only things that happen in a specific date and time. Todos don't belong here - they belong in a todo list.
- Form a habit of looking at the calendar daily, and have it timely alert you on important things.
- Have a single calendar.
I use Google Calendar. A physical calendar is totally OK. No alerts then, though.