Making a duck tape ID holder is super easy. These aren't anything grand, they're just a simple card holder. Personally, I'd make several of them at a time. Get out all of your colors of duck tape and have a party. Takes longer to take out all of the materials than to actually make one.
Duck tape - the more colors the better
Without a doubt, you should use a rotary mat and cutter. It'll make the project so much easier.