Standard wood drills (as in this photograph) work well for cutting neat, point centralised plastic-card port holes, as good as they do for wood or MFD etc. (instead of high-speed steel drills, which can end up a mess).

For clear plastic glazing to match these ports. I use circular punch's which cut neat clear round plastic glazing to fit, also for cutting round plastic-card for circular objects etc. I have found that it works better if punched with a hard hammer tap onto a flat hard-wood backing.

Photo examples and tools. These tools are both available on-line in sets between 3mm and 8mm.