And here's an excuse to spend three hours in the trim department of a fabric store: trim detail. There are so many choices from tape to tassels to gimp; I usually recommend going with 1.5-inch woven trim. This size makes a pretty big impact on a small-to-medium sized window and usually falls within the $8-$12 per yard range.
Tip: Trim can get pricey. If you're just doing one window, go ahead and trim all four sides of the shade. If you're dealing with multiple windows, one strip at the bottom will do just fine.