Cut a nice strip of a can.
Get your stencil for your necklace and draw around it with a compass so that you lightly draw a line
Then cut that out
Get your foam and draw around the coke stencil. Cut this out too
Then pucnch a hole where you want your jump rings to be. Make sure it is on the same place as the foam
Then glue the tho together and put your jump rings through