The Rectangle
(the H shape)

Has little or no waist definition.
No waist details. i.e. no belts at the waist.
Look for long tops that sit past your waistline around the hip bone.
Tops should be shaped to create the illusion of a waist. i.e. crossover tops.
Look for tops that have detail on the bodice, the focus should be on the top half of your body.
Jackets and Coats should be shaped through the waist in the construction
Lower button closure will give you a more defined waist.
Skirts that compliment your figure are asymmetrical, ruffled and straight styles.
Pants should be straight leg, boot leg or wide leg
The most flattering will depend on the length of your leg and the size of your thigh.