If not a centerpunch, try a ball mill or bur to start the hole. If you don't think they make 0.9mm, 0.7mm, 0.5mm and smaller ball mills, go ask your dentist for his old ones. They used to sterilize and reuse bits until they got dull, but they aren't allowed to reuse on patients anymore. Every little cavity and a new 3/32" shank carbide bit goes in the trash with only seconds of use on it.
Ask him to save up and autoclave (sterilize) his old ones for you instead of trashing them and a week or two later you should have a lifetime supply to play with, even if you live a very long time!