I don't know about anyone else, but in my family holidays are pretty laid-back affairs. Thanksgiving usually consists of hanging around at my brother's apartment, drinking and watching the National Dog Show (which is more important than the parade, in my opinion) until dinner is ready. Once everyone has a few cocktails in them, we might play some Cards Against Humanity.
There's no reason to dress up, so I usually opt for something casual and comfortable. Those Old Navy sweatpants are a dream -- especially with that waistband after dinner -- and the ModCloth t-shirt is comfortable but still looks cute. The boots are, unfortunately, a necessity in case that forecasted snow turns up. The tote bag will nicely carry all the things I need (books, knitting) to ignore everyone when I've reached an overload of human interaction.
It's stuffing time.