Shrinky Dink sheets from the craft store
wire rings (I used pre made pieces from the jewelry section)
needle nose pliers
Don't create your tags any larger than a 2" x 2" square. Otherwise it will curl up and not lay flat.
Remember that each image shrinks down to about 50%.
Don't forget to punch a hole in the image BEFORE you shrink it.
Keep your heat gun moving so than you don't over heat it. It will burn.
Of course you can always use the oven. Just follow directions from the manufacturer.