Let's talk about drilling interior holes. In most hardware stores to can buy 1/16 or 1/8 inch diameter drill bits. Sometimes these are too big for patterns with very small interior cuts. We have super fine blades and we need super small bits. Luckily we can buy micro bits for this purpose.
The bits are sold with a numbering system. The higher the number the smaller the diameter of the bit. A #72 bit is .025 inches in diameter. That's really small. You can buy a set of bits or buy the sizes you need most often in quantity. I recommend figuring out the sizes you need and buying them by the dozen. You won't need all the sizes in a set and they will break so buying in bulk is the best idea.
One issue with these small bits is that they won't fit in a standard drill press chuck. There are a couple options for this problem. You can buy a hand vise and drill the holes by hand or purchase a micro chuck and use that to hold the bits in your drill press.
The picture below shows a set of micro bits, hand vise and micro chuck with different size collets. There are a couple different types of hand vises. The one in the picture below uses a spiral shaft to spin the bit as you push down. You can also buy a hand vise that requires you to twist the bit manually. Watch the video below to see a demonstration of the push hand vise.
You can purchase these bits several places online. Sloan's Workshop is one choice. Mike's Workshop is another excellent source.