What Matthiewagg said a 1000%. That's the way to go. New land needs to FEEL alive, and polished. Otherwise, everything might seem out of place. Also, I like new unique items. You know, custom armour, weapons, amulets etc etc to really get the feel of new content. It is -very- imoprtant though to keep the Vanilla-Skyrim-Vibe when implementing new models, meshes and textures imo. Also, a nice easteregg or reference or hidden gem from time to time always make a mod more charming :)