My favorite women's travel outfit: black yoga pants with front pockets (Lululemon athletica has some great quality ones- flat seams, soft, exceptionally comfy), a light long sleeved t-shirt (in black), and a spiffy Talbots embroidered fleece. Dark colors are great to hide any stains. The tops need to be long, so when getting something out of the overhead you don't show your belly to any googly-eyed men hoping to get a peek. In the summer, the light long sleeve shirt can be perfect for cold flights, and you just push up the sleeves to cool yourself when you get off the plane. I wrap the fleece around my waist if it is too hot, and almost always I have to wear it on the plane.

Just make sure everything is clean and not faded and you'll feel great. I've never seen the FA's treat folks shabby for being dressed casually. I sense that if you feel great and throw out a good vibe, the FA's will respond and treat you well... just as you expect to be treated.