The one question for guests before attending the viewing party: Are you a Blair or a Serena? Basically, are you a Betty or a Veronica? An Audrey or a Marilyn? The answer was clear when the doorbell rang and the door was opened to a headband and a skirt or pumps and skinny jeans.
When hosting a viewing party — whether it's for a show like Boardwalk Empire, Glee, Modern Family, or Game of Thrones — if you have guests dress to impress like their favorite character or in attire from that era, you can skip the decorations, as the clothes will create an ambiance all on their own.