Marbled.

I've been meaning to try water marbling, it being one of those techniques that's so common but I'd never attempted it myself.

Estée Lauder - Blue Dahlia, Catrice - C05 Take It Mint

I then attempted it.
And sucked, terribly.
It was somewhat of a blow to the ego to find out there was a nail art technique I didn't just miraculously take to without all that much effort. It appeared I'd met my match. I did not quit, however, and gave it another shot.
This was my third try. I think it's okay. It is successful inasmuch that it has the marble effect on the nail.

It's not really my technique. Don't get me wrong, I think it can look absolutely amazing but when it comes down to it to me it's messy (which I hate), uncontrolled (which goes against my nature) and rather wasteful. One has to test a fair amount of polishes before you even find out what works with this, and then if you want to do more than two nails .. that's a hell of a lot of drops plopped in water, you know? To me, at least, the amount of nail polish expended is not worth the result. I may experiment with it again in the future, but probably not for more than accent nails like I did here. I can't imagine bothering with a whole hand, let alone two.