In addition, you will some thing to cut the pictures into the layers. You can use small scissors but I used a craft knife and a cutting board.
You need to decide which parts of the image will be on which layers. It helps to write these out to help you decide how many prints you need to make for the layers. It also helps to keep track of what to cut off of each layer.
I was going to do five layers. I had a sixth layer that I was going to do using regular double sided tape but ended up using the foam tape for that as well. Starting with the full image, I stuck the next layer down on top of it. The I kept sticking down the smaller layers until I was done.
I used the double sided tape to stick it to a card for the backing to help keep it centered. I ended up using a comic backing board. I had picked up a couple of extra boards to use for the layers in case the tape was too thick.