A pencil skirt is flattering and versatile for the office. You can wear it with a feminine blouse or masculine shirt tucked in to look put together and stylish. I love gray skirts because it's in between white and black, and it goes with every color. It also look professional and I usually opt for tweed or wool fabric because it's classy, wrinkle-free and the quality last longer. For inspiration, take a look at Stylishlyme blogger Vanessa Rodriguez on how she styled her all gray attire.
When choosing a pencil skirt, there are two things you need to consider: fit and length.
1. Fit - The skirt should fit around the waist and hips (not too tight)
2. Length: Slightly above or below the knee.
Styling it: Tuck your shirts to create a slimmer waist and more sophisticated look. It also give an illusion of longer legs.