I used the craft canvas and report cover binders with aquarium sealant to keep them in place. I find attaching java moss or christmas moss to them works extremely well. As the moss grows, it starts poking through the other side of the canvas as well, making a lush mossy wall. I also sewed the leaves from silk plants onto the canvas--this works fairly well but keep in mind that most thread will eventually deteriorate into nothing and the leaves will fall off eventually. You can use fishing line, but it's rather difficult to sew with, lol.
I'm satisfied with attaching my dividers with aquarium sealant. Make sure the packaging states that it is specifically for aquarium use and allow it to cure for 24 hours before you fill the tank with water.