This might sound like a bit of a cop out, but I never go for elaborate nails. I keep my fingernails cut short due to all the circus and such that I do, and IF I paint them, it is always just a solid color. I do like lots of different colors though, so as I do when I accessorize, I will focus on the more subtle colors in a print, or contrasting colors.
If I am wearing all blue and accessorizing with silver, I will probably paint my nails silver as well.
If I am wearing something like my Infanta Sleeping Beauty JSK, I might go with a brown, but it is more likely I would go with a pale pink or green to match the vines.
If I were matching a theme, either set by a meet-up (such as when the MLS anniversary dinner had the theme of gold), or by an outfit itself (such as a chocolate print), I will likely match that theme (gold or chocolate colored, respectively).
I do admire the elaborate nails that I see on other girls, but my nail polish never lasts more than a few days, so I do not see the point on myself, but I definitely love to see them. Were I to go for the more elaborate, or to recommend for someone who does, I might do some roses for Sleeping Beauty.