Do you or someone you know have an old, oversized t-shirt lying around? Or an oversized button-down? Then consider turning it into a boxy crop top. These are great and super easy to make. All you need to do is cut from the bottom of the shirt, and you have a brand-new crop top. Of course, you'll want to make sure that you cut off enough to get that boxy look we see below.
If you're feeling particularly brave, consider making curved cuts along the bottom or just using a printed t-shirt. Both are great ways to add a little something extra to your crop top.