On the off chance that you haven't heard of the drip marble technique, the super awesome tutorial video from My Simple Little Pleasures can be found here. All you need is some nail polish and some plastic lids.
I only used three polishes for these: Powder Perfect Puerto Rico, Watchful Nights and Color Club Almost Famous. The yellow looks a bit more washed out than it did in real life. Almost Famous is one of two yellows I like using for nail art since it's so bright and opaque.
That's all for today! I hope you like these as much as I do. For more contrast nail art, check out the rest of the group's designs in the links below.