i have been carrying around a big clear plastic tarp yanno, in case of emergency and sometimes i use it as a nightcover over my gear under the main fly because at night your stuff gets damp if you don't or if it rains sideways any tarp high enough to make comfortable living won't keep out sideways rain but the thing didn't have grommets, which kept me from using it as an awesome tarp over my hammock so then while i was on site 27 i decided to grommet that puppy up BECAUSE I CAN.
so first you reinforce the corner where you're going to put the grommet. i used clear gorilla tape.
then you pinch a hole in the corner with your hole-punching die and you stick the brass piece in there on the grommeting anvil with the sticky-up bit going through the hole and the donut bit on top and you slide the mandrel right in there and start hammering away, turning it a quarter turn each strike just to keep the thing even as the metal crimps.
and you're done.
what i have learned is that nearly every job looks arty if you photograph it on a cut log against fall leaves.