I made a small sander attachment to be used with my dremel rotary tools.Sander can be mounted to my diy dremel lathe, or it can be used without it. Its light weighted and easy to take outside, i like to work outside in the summer, so good mobility is a bonus. With cordless dremel it really is very mobile.
Dremel 7300-N/8 4.8-Volt Cordless Dremel MiniMite Two Speed Rotary Tool /Directions-. I like the #432 tube like discs and the ones just a tad finer grit the most . The 432 needs a super light touch, you may start with the finer grit till you learn more. It will be safer. What you need to learn is to tap and move on, from one nail to the next and back again. If you hold steady you can burn them, as it will get hot. So just a short hold,and on to another nail.
Kim - I used a cordless dremel to drill the holes - I use a scribe first to punch a divet in the penny. You can't do a lot of them before the dremel runs out of juice, but for getting started it works!