I'd take four layers for up top: maximum 2 t-shirts, a zip neck wool or synthetic top, warm fleece/down/synthetic vest, and a gore tex jacket. I'd possibly also take a lightweight button up shirt for hiking when a wool shirt is too warm but a t-shirt is too cool.
and four layers for the bottom: maximum 2 pairs of boxers, lightweight tights/long underwear bottoms (I prefer Capilene), hiking pants (no cotton!), and gore tex pants (if you got 'em... if you don't have any, I'd take a second pair of hiking pants).
Throw in two pairs of socks, a beanie, and your lucky fishing hat and you'd be set for anything the Smokies could throw at you in the spring time.
Also, I like to bring along a fresh pair of jeans, boxers, a t-shirt, and some flip flops, which I leave in the car to change into after it's all over. Fresh clothes after a few days in the woods feel almost as good as a cold beer after a long hike! Especially if you're soggy.
Grannyknot is dead on about the socks... it ain't worth skimping in that department, and those smartwool hiking socks are dominator. Also, never pack anything cotton. That is the worst possible back country fabric ever.
I got no style, I'm strictly roots.