I insert a lot of eyelets and grommets into my project using the Dritz Eyelet Plier Kit. And every. single. time, I have to get out the directions. At first, I copied the back of the package and laminated it. I put that into my little "grommet/eyelet" basket were I kept them. Even so, I'd read and re-read out of fear that I'd do it incorrectly.
The other day I was adding some eyelets to a hanging shoe organizer that I cut up so it would fit going down my stairs. And it finally hit me: write on the pliers (Deep Half goes on the Right Side - Shallow Half goes on the Wrong Side).
BTW, I love my label-maker, too.