Grommeting pliers

These look like regular pliers, but are used specifically to put in grommets. (And here you thought that the only Gromit you needed to know could use some walkies.) It cuts a hole in the material (like a regular paper punch) and then presses two metal rings together to form a grommet. The metal rings overlap, creating one smooth rounded ring, and form the "edge" of the hole. This reinforces the hole, protecting it from getting stretched out of shape and keeps the material from fraying.

If you own a pair of lace-up boots, look at where you run your laces. Odds are that the holes have grommets.

To use grommeting pliers, put two grommet rings (a top and a bottom) into the 'teeth' of the pliers, position the tool over where you want the hole to be, and squeeze the handles together. This is a bit hard if you've got small hands or don't have a lot of hand strength. If you have a ready victim -- er, assistant nearby, you might want to get them to do this part for you.