I started with a base of Barry M Cotton, and then watermarbled using Pink Candy, Purple Pop, Orange Fizz and Cherry Drop.
As you can see, they work really well. I'd wondered before about water marbling with sheer polishes, but the OPI Color Paints I have are only minis, and I wasn't keen to waste loads of polish. The Barry Ms are a fraction of the price, and are easier to replace, so I went with those. Plus these smell pretty!
What do you think? I really love how these look, and I'll be doing this again. I wish they did a green and a yellow as well!