I think using black, white, and a couple bright colors worked well! I didn't even splatter with the blue, I just used it as my base color. The splatters remind me of Jackson Pollock's artwork.
I started off with two coats of Wet n Wild I Need a Refresh-Mint. Although it's called "mint," it's pretty blue to me, but I love the color! I then splattered Wet n Wild Black Creme, French White Creme, and Through the Grapevine, all in that order. You can tell that I use the black and the white polishes quite often - the labels are rubbing off!
As for technique, I just used a drinking straw. It was a pretty thin straw, but I actually wish I had one even thinner, more like a coffee stirrer. My only problem was that when I would dip the straw into the polish, it wouldn't really make a bubble or layer of polish across the hole. So when I would blow through the straw, nothing would happen. I think the polish would reach across easier if it were a smaller straw.
But after several tries, it worked! I just had to keep dipping the straw and trying. It didn't take too long, and I like the finished product, so I think it was worth the effort. I'll just get coffee stirrers for a future attempt!
It was also a bit messy. I forgot to put Vaseline around my fingers, so I ended up getting polish around my nails. You can see where the black started to seep in around the cuticle, and started to stain part of my pointer finger! I would recommend using Vaseline or tape around the nails for easy cleanup.