Try this KEEP IT SIMPLE HINT

SETTING EYELETS, RIVETS, SNAPS without smashing

The one thing manufacturers of eyelet-setting tools fail to mention which, in my opinion, is the key to setting eyelets without them becoming smashed or mis-shapened is:  don't try to set them with one big bang!  Instead, use several lighter touches with hammer or tool, then turn over and give the back of the eyelet a gentle tap or two to catch any uneven edges.  Try it!