Blouse: Something comfortable and flouncy, that breathes but isn't super thin. T-shirts not allowed.
Love this: Diane von Furstenburg Orange Blouse
Long scarf/Pashmina: Wonderful for fluctuating temperatures in airports & on airplanes, and super light to carry around. Throw it on when it gets cold, throw it off and stick in your bag when it is gets hot, use it as a blanket to sleep with on a cold plane, or roll it into a ball to make yourself an instant in-flight pillow.
Flats: I see lots of really beautiful women in sky high heels when traveling... if you're one of them,more power to you! Walking in heels for hours can be tiresome and painful, so pack flats. I really think the most comfortable flats in the world are by Lanvin. Zara makes great substitutes.