Black or white tie is the perfect chance to get ridiculously dressed up. Tuxedo nails are A Thing, and one I haven't done, but I recently discovered an even cuter alternative, featuring the currently- and recurringly-popular Peter Pan collar. As this style looks really silly on me in clothing, my nails offered a good opportunity to rock it.
I roughly followed this tutorial and was pretty happy with the results! Trying it again would pay off, but it took some time and it will be awhile before I am motivated enough to do that, I think.
And my right hand:
They look best from not-too-close-up, I think.
The black is Revlon Colorstay Stiletto, which went on really easily and well. The collars I painted on with Konad Special White, and used silver microbeads for the buttons.