Set a one year rule on the unfinished stuff. If you haven't touched it in a year, sell it or toss it. I do that with my woodworking scraps and half started projects. @knight.uma is right that the middle is where you figure it out, but after a full year you already know if you're ever going back to it. Keeps the garage from turning into a storage unit for broken intentions. The $45 birdhouse is a good example. Either finish it or free up the space for the next thing you actually want to do.

Man @perry.jesse you nailed it with that one. For me it was with a used car I bought without getting it checked first. Engine blew two weeks later and I was out like $3,000. After that I never skip a mechanic inspection no matter how good the deal looks. Sometimes you just gotta pay that stupid tax to really get it.