I just sent a reporter some ideas for what to wear to a summer barbecue. Key thought: Remember where you will be and dress appropriately. In the city, in the street? Think more structure, darker colors, etc. In someone's backyard, I suggest a pretty floral dress, like this one by Nanette Lapore, thong sandals, maybe with some embellishment, and a hat. You can then take the basic formula — pretty, bare dress + sandals + statement necklace — and dress it up or down, for day or night.
Only problem here is I think this purse is too structured for this occasion — what do you think? What would you wear to a summer barbecue?