How do you make nail polish remover?

Unless you're making it in fairly large batches (i.e. producing it for sale), it's probably going to be cheaper and easier just to buy it since it's much more readily available to the average person than the ingredients themselves are. However, most of the ones currently on the market consist primarily of acetone, ethyl acetate, or a mixture of the two (MEK, methyl ethyl ketone or 2-butanone, would probably also work). They may also have fragrances or dyes, but those aren't technically necessary.