From my cyber-friends at RealSimple comes this helpful slideshow, Festive Outfits for the Holiday Season. And when I say “helpful”, I mean it: the focus is on using just one key piece—which may very well be in your closet already— to create new party-worthy ensembles. The clothes they show include links to buy them, and with prices starting at just $50.00, these options are practical and affordable!
The slideshow categories are The Colorful Dress, The Embellished Jacket, Dressy Pants, The Black Dress, and The Long Skirt (the photo below is one example).

The Long Skirt. Remember Sharon Stone wearing a fancy long skirt and jewels with a plain white shirt (from the Gap, I think) to the Oscars?? At $198.00 (the slideshow said $149.00), this is the priciest item in the slideshow, and you can find it on Piperlime. (Click the photo to go directly to the slideshow.)