Steve and I started incorporating a sinking fund line item in our budget about six months ago. Oh. My. Gosh. Why haven’t we started this sooner?   So, if you don’t know what a sinking fund is, it’s an amount of money you save every month (or week, two weeks, whatever) for expenses that only come up once in a while. We all have bills like insurance, oil changes for our cars, and things that are only paid every few months. We know they are coming so instead of flying by .