Next I grabbed some square peel and stick tiles with a neutral-looking pattern. They make faux wood, but this space butts up against our engineered hardwood floors, so I didn't want it to clash—wanted it to be totally different and just look like a more polished concrete.
I laid the majority of the closet's floor without cutting any pieces, starting from the back corner. (As one helpful commenter pointed out, you should start in the center, but I'm not a professional at installing floors and just wanted to get this vinyl down in my tiny closet.) I started by peeling the backs off of each tile and laying them carefully onto the floor. Yes, that’s it, I peeled and stuck...my peel and stick tile :)