I cannot exactly call this a formula because I only have 2 dresses like the one I am wearing, but this dress plus a cardi or denim jacket has been a favorite since I picked up this dress 3 years ago at (say it with me!) Old Navy. The cardi is from the ON as well. I am also wearing red lace ballet flats.
I almost did not buy this dress and it's twin in black because they have spaghetti straps. There are plenty of admonitions out there warning busty women not to wear dresses with spaghetti straps -- but I ignored that when I saw how this dress fit. Why should I leave behind a perfectly pretty dress simply because of a thin strip of cloth that no one has to see? I also love the drawstring which helps define a waist and the ruffles down the front. Sounds like a lot going on when you throw in the print, but it works.
I usually wear this dress with a regular bra because strapless bras give me a strange profile and don't really lift and separate. So when I wear this dress with or without a topper I wear a bra with coordinating straps. I don't generally encourage women to wear a regular bra with spaghetti straps because I have seen it done badly so many times. How do you all feel about that?