|I've gleaned tips about installing rivets from multiple reviews of jeans patterns. This technique is mostly a compilation of other people's ideas, so thank you in advance if you see a familiar tip!
1) Rather than attempting to clip the pin to match the thickness of denim, use denim 'washers' from fabric scraps to add depth. I applied fusible stretch (knit) interfacing, which I hope will prevent fraying. For the jeans that I made, I needed about 5 layers of denim.
2) Make a hole in the fabric using an awl before trying to hammer anything together. The rivet pin is too dull to pierce fabric.
3) I was all ready to go buy some kind of anvil for jewelry making until someone suggested using a dumbbell plate. I think even the bottom of a cast iron pan would work. I laid scrap fabric above and below the rivets to avoid marring the dumbbell surface or the rivet.
4) The rivets that I purchased had a little belly button (not quite an innie nor an outie). The pin pierced right through the belly button if I didn't have enough layers. In a similar vein, if I had too many layers, the rivet cap would pop off the pin, even with a few gentle taps.
5) If you are like me and can't hammer a nail without bending, it will be easier to tap the rivet cap onto the pin rather than tap the pin into the rivet cap. Also, a bunch of gentle taps is better than a few slamming hits because (in my hands, anyway) the pin was more liable to bend irreversibly with a slightly off-angle slamming hit.
Hope this helps someone!