You don't have to dwell in Fallout 4's wasteland for long to realize that the most valuable commodity isn't caps ... it's glue. More specifically, it's adhesive, and you need it for almost every modification you'll create — and there ain't a whole heck of a lot of it scattered throughout irradiated Boston.
Luckily, a savvy Reddit user named jredwards has found a way to collect unlimited adhesive without a heck of a lot of work. The secret is a cooking recipe for "vegetable starch," a commodity that breaks down into a whopping five adhesive. The hook is that vegetable starch is composed of ingredients you can grow (read: infinitely replenish) at one of your settlements.
The only outlier is purified water, but jredwards' post has some tips on workarounds for that, as well as a complete walkthrough of how to optimize your adhesive and get back to sticking junk on other junk to your heart's content.