Nancy- depending upon your budget and plans for "production" volume, you might consider purchasing a small Roper Whitney Jr metal punch.
https://www.roperwhitney.com/our-pro...-punch-in-kit/
The kit comes with a number of different size dies sets that make popping numerous accurate holes in sheet metal & aluminum a breeze- especially if you clamp it in a vise or mount to the bench. The larger XX version has more throat capacity and can be kitted with similar dimensioned die sets, but is more expensive. Before i got a real RW punch, I had a knock-off version that I bought second hand. For certain size holes, the dies never lined up right so would either not make a full cut or leave a bad burr. If you buy one, get a real one.
Unlike drilling holes, a real RW punch leaves no sharp edges that might injure a tender nose.