Kristen Bell is also wearing a very smooth-looking medium length hair style.  She has pulled back small sections of the hair in front, leaving her face open.  The ends of the hair are flipped out in the back and sides and flipped under in the very front.

Kristen also has a few bangs that are cut about eyebrow length and are gently swept to the side from a deep side part.

Jessica Simpson is wearing a very smooth and sleek medium hair style.

She has used color highlights on the ends of her hair for added effect.  You could experiment with the wash-out hair color and just wear the color for special occasions instead of committing with permanent coloring.

Jessica's hair is cut to a medium length with the sides angling down from about the cheek level. 

The hair is parted deep on one side and the hair in the crown area has a little bit of height added with back-combing.

Side swept for fringe bangs would also look good with this sort of hair style.

See More Medium Hair Styles