Those of you who use a mostly paper system, how do you manage recurring tasks? I'm thinking more menial stuff like changing your furnace filter, watering plants, et al, that you might need to do once a week, every month, etc.

I've been using kGTD lately and really appreciate the way it distinguishes between tasks that recur after a certain number of days no matter what, and one that resets a certain number of days after you last completed it. How do you manage something like this on paper, besides (the horror!) remembering to repeatedly write them down?