So this is what I do (which I'm sure has been thought of and done before - in fact YOU probably already do this, but my sister gave me such an odd look about it I thought I'd share just for kicks)...
- Things that need to be replaced monthly I replace the first of the month (contact lenses, baking soda in the fridge, vacuum filter, and I wash my makeup brushes).
- Things that need to be replaced every 3 months I replace Jan-March-June-Sept (toothbrush, mascara, oil changed, and I get my ring cleaned).
- Things that need to be replaced every 6 months I replace in March & Sept (running shoes, socks, sports bras, I get my tires rotated, and vacuum serviced).
- Every two years I replace (and this is staggered) towels, pillows, bath rugs, and sheets. These I usually do in June (wedding season) or January (after Christmas sales) and it's easy enough to remember if I didn't replace it last year then I need to replace it this year.
And that's my little system. I think for the most part it keeps me in good running shoes and with a vacuum and car that work. Everything else is just a bonus :)