I've blogged about a make-shift small parts planing board that was specialized for mitered boards, but the point there was making something disposable for a special purpose.
shooting board, I took some of the scrap to make a less-blingy planing board. Basically, I hand planed some cherry scraps to 1/8" and 1/4" thickness then lined them up across the end of a board; these act as the fence and give me some options for thickness.
You'll notice that I used hide glue for the fence. During use, it'll get shredded. Once it's too bad, I can use a heat gun to quickly remove the fence and attach a new one.
This is a super trivial addition to your shop; make one now.