Order a size up
Ordered a small and it was much too tight on my chest. Also didn't quite like the material/pattern/color of the dress in person so I returned it rather than exchanged.
Response from Lulus.com:
Hi Katy, thanks for your review! We apologize that the fit of this dress wasn't quite right for you. Our fit experts (lulus.com/customerservice) are available to provide personalized assistance for all of your sizing needs. We're in the office daily, and would be happy to help! XOXO