I use an electronic calendar for most things, but I have a problem when it comes to long-term planning — my important trips get lost among the day-to-day appointments on my calendar, and I end up double-booking myself. So I made some old-fashioned, yearly calendars which I print out on large-format paper and tape on my wall. Then I can cross out days when I will actually be away, completely from the office. An example is to the right (or perhaps above, if you’re using a small screen, like a cell phone).