Measure the spacing. Measure the width of your curtain panel at the top. The width divided by the number of grommets gives is the distance between the center of each grommet. (Width/ Number of eyelets = spacing)
Mark the spacing. Divide the spacing number by 2. This is the distance from the side edge to the center of the first ring. Mark the rest of the eyelets adding the full spacing measurement to the previous mark.
Decide how far down to put the eyelets. Use a template and an eyelet to determine how far down you want ring (measure for the center of the ring, not the edge). Write down this measurement and mark the center of where each ring will go.
Draw a circle. Using the fabric marker or sharpie on the backside of the curtain, line up the center to your dot, and draw a circle using the template.
Cut the circle out with scissors. Fit the ridged side of the eyelet inside the circle. Tuck in or trim any loose fibers.
With a lot of pressure, press the spiked grommet into the second grommet. You may want to do this on a softer surface like a padded carpet or folded towel.