The bigger, the better. And yes, wearing them all at the same time is imperative. Take cues from Becs of Style with Benefits.
Scroll to the third photo to see what I'm talking about (or the top image here). I poked around Forever 21 to see if they already sell the bikini top. It seems that we might still wait for some time to be able to buy this.
Here is a cheap find courtesy of Erika. I am definitely going for the Forever 21 pair because they cost only $24.80. The color is better, too!
I am referring to the black piece with a crocheted neckline. Very sweet and demure on the front but when you turn around, the dress gets its flirt on.