BALL GOWN -
The most traditional of all categories, the ball gown is typified by a full bodice and a waistline that leads to a very full skirt 
(see photo below)

 

EMPIRE -
The hallmark of the empire style gown is a high waistline (right under the bust) which falls to a slimmer skirt 
(see photo below)

 

A-LINE OR PRINCESS -
An A-line or Princess shape features vertical seams flowing from the shoulders down to a flared skirt (creating and inverted "V" -- or "A" -- shape 
(see photo below)

 

SHEATH -
The slim sheath silhouette closely follows the line of the body (see photo below)

 
 
 
 
 
 
 
 

HOURGLASS
You have a big chest, big hips, and a thin waist
(i.e. curves in all the right places).

Dress Dos: An A-line dress or a gown with a dropped waist will show off your figure; pair it with a sweetheart neckline to exhibit your chest.

Dress Don'ts: A ball gown or empire waist silhouette may make you look disproportioned.

SHORT WAIST
Your body is naturally proportioned, except the small distance from your ribs to your hips.

Dress Dos: A princess-line silhouette -- fitted at the bodice and opening up gradually to a full skirt -- elegantly elongates your figure; if you love your shoulders, try a portrait or halter neckline.

Dress Don'ts: A sheath will make your short waist more obvious.

THICK WAIST
Same as above, but instead of a short waist, yours is undefined: the line from your shoulders to your hips is straight.

Dress Dos: An empire-waist gown will de-emphasize your waistline and give you a long, thinning look.

Dress Don'ts: A princess-line or basque waist will draw too much attention to your middle.

FULL FIGURE
Full breasts, a bit of a tummy, round hips and butt.

Dress Dos: A ball gown will hide quite a bit, and an A-line silhouette looks great on everyone.

Dress Don'ts: A sheath will make you look heavier than you are; avoid spaghetti straps.

PEAR SHAPED
You're small on top and heavy on the bottom.

Dress Dos: A basque waist or strapless ball gown will cover your bottom half and focus on your better half; an off-the-shoulder neckline will make your top more in proportion to your bottom.

Dress Don'ts: A sheath,  will be unflattering, and a V-neck will draw the eyes down.

THIN
Short or tall, you don't have meat on your bones.

Dress Dos: A ball gown will make you look like a beautiful ballerina, and the sheath was made for you.

Dress Don'ts: Almost all silhouettes will flatter your figure, but stay away from portrait, off-the-shoulder, or halter necklines if your collarbone is too bony.

PETITE
Description: You're not a basketball player.

Dress Dos: It's best to keep it simple -- when you're small, a big, elaborate gown can sometimes look as if it is wearing you rather than the other way around. A sheath or A-line dress will work well.

Dress Don'ts: Almost all silhouettes will flatter your figure, though a big ball gown may overwhelm.