Denim pencil skirts are like jeans. With tops and footwear you can dress them up or down. A graphic tee under a jacket (any kind...blazer, leather, military, etc,) and sandals, booties, boots, loafers, pumps, etc. Depending on the weather and the look that you want.
A silky top semi- tucked with a belt, a turtleneck, assymetrical tee, buttondown shirt of any sleeve length, about any type of top can be used.