Keep in mind that all of these suggestions are guidelines, not rules. It is exceptionally rare that someone is a "perfect" triangle, rectangle, inverted triangle, hourglass, or oval. It's just a place to start. In the end, it's all about creating (or maintaining) balance. Get to know and accept your body's natural shape. By doing this, you will consistently better understand how the things you wear will look on your unique and beautiful shape.
The triangle shape, also commonly known as a "pear" and can also be a "spoon", carries the majority of their weight on their hips, bum, and thighs. This can often make shopping for bottoms (jeans in particular) frustrating as they seldom form fit just right at the lower back.
With a smaller (at least proportionally) bust, the goal is to draw the eyes upwards and create a visually even body shape. Bows on or right under the bust line draw the eyes, as well as low, cleavage revealing tops and cropped or hip length jackets.
Avoid items that will make your lovely waistline disappear. Empire waisted babydolls will flow outwards from your bust and sit on your hips and take away all shape in your midsection. Stretchy items with a fitted waist and embellishments around the shoulders and bust will hug your curves and add balance.
A-line skirts and dark denim are your friends. Minimize the attention to your lower half, but don't try and hide it or you may end up making it look larger. A high cut lingerie bodice can add shape to your hips without covering them up.
Rectangles, sometimes called "ruler" shapes, have balanced bust and hip proportions and a very slight or undefined waist. Your bottom is likely flatter, instead of rounded and you probably have shapely and slender lower legs. This is the most common shape for American women.
Anything you can do to pull in an enhance your waistline is your goal! You'll immediately create a visual hourglass.
Tops that are flow-y around the bust or cleavage revealing with a cinched waist will visually flow and create shape. Off the shoulder shirts, wide necklines, and strapless corsets will lengthen your shoulders and create the illusion of a smaller waist.
Look for pencil and A-line skirts (not straight) with a cinched waist. Pants with large back pockets will make your bum appear more rounded.
Your shape tends to have a much larger upper body (bust and shoulders) than lower body. Your hips are small, your waist is not dramatically defined and your bum tends to be more flat than rounded. Your legs are likely slender and shapely.
Tops that are V-necked can accentuate your lovely bust line and visually move the eyes towards your waist. Halter tops will hug your bust without create distracting amounts of cleavage, taking attention away from your hips. Lingerie pieces with cut out sides will give you a more defined waist line.
Balance these tops with volume boosting bottoms, such as gathered or pleated skirts and wide, slouchy bottoms. Avoid pencil skirts as they will only bring attention to smaller hips.
Luck and genes are on your side! You have the rare balanced body shape that were all trying to achieve. Your bust and hips are almost exactly the same size and you have a well defined waist. Your bum is likely rounded, but not larger than your bust and your legs are shapely.
Your goal is to dress your top and bottom proportionally and accentuate your pulled in waist. You can wear snug and slinky items with little embellishment needed. Like a triangle shape, avoid items that are empire waisted and hide your curvy waist. Corsets are an excellent choice as they pull in your waist, but do not minimize your hips.
The world of pants and skirts is completely open to you! Keep in mid that if you choose something with lots of volume on the bottom (and likewise, if you choose something tight fitting) make sure you choose a balanced top and mind your waistline.
Oval shapes have a fuller midsection and often (though not always) a larger bust. The key is to deemphasize the midsection and visually or physically create a more defined waist. Don't be afraid to emphasize your attributes, such as your shoulders, legs, and bust!
Empire waisted babydolls look fabulous on your body as they draw attention to your cleavage, flow nicely over your midsection and hips and show off your legs. Belted items can pull in your waist nicely and create proportion. Deep V-necked tops will show off your assets and visually create a smaller waistline.
Pocketed cargo-type pants and slightly flared skirts will draw the eye away from your waist. You can also wear pants that hug your hips and bum but make sure the legs are straight, not tapered and choose a higher waisted pant to avoid creating a large muffin top.