your cardigans should hit at the hips to elongate your torso and shorten your upper body. Try a V-neck to show off a little 'somethin somethin'-remember the secret is subtle cleavage not covering everything up
A PETITE FRAME
Try something like a crisp button down underneath to add volume and balance out your hips. Cropped cardigans with V-,scoop and sweetheart necks all work for you, congrats.
Open cardigans balance out your shoulders. Shop for one with large button, like the cardigan on the left here, or a hood to keep your look vertical.
Three words: layer, Layer, LAYER! This hides the 'pooch' without adding unnecessary bulk. Let the clothes under peek out of the cardigan too. And remember, whatever you wear underneath, keep it untucked and long.
Never wear cardigans that hit you on the largest part of your hips. This draws the most attention to this area. (Not to mention it makes it impossible to sit if something has a death grip around your hips)
Short sleeved cardigans+buttoned up= bad. This especially applies to the hourglass and fuller busted woman. It causes the cardigan to bind and pull at the buttons, making you seem larger than you are. Its just a big no-no.