From the few occasions I am forced to pimp myself, I can recommend you to the "Dead sea cosmetics" nail polish set. So instead of adding some sort of chemical polishpaint on your nails, there is some sort of stone that you use like a very fine nailfile. So instead of adding chemicals to your nails, that they seem to be polished, you are really polishing your natural nails. There is also some sort of oil in the set, you can use if it feels good for you, but its only additional. The set was quiet expensive (about EUR 25,--) but I have it since 3 years, and the "stone" is still fresh.
Naturally it wont function if you already have paint on your fingernails, because you cant polish your fingernails if they are already under a layer of paint.