R.J.
Simple + Pearls = CLASSIC
I would suggest sweeping your hair up if it's medium length, but leaving it down if it's long (<grinning> or obviously if it's short... but if it's very short... "sleeking" it).
Sheath dresses are about the most versatile dresses on the planet. Pair it with pearls, dramatic eyes & lips, and heels, and you're set for any nice restaurant in the western world. Toss on sunglasses, sunhat, and sandals and you've got casual summer wear. Boots and a short leather jacket and you're clubbing. Filmy scarf, broach, and sandals and you're at brunch. Sensible shoes and a blazer and you're at work. Leggings, sneakers, belt, and backpack... and you're on campus. TOTALLY versatile.