No matter what size you are or how much you weigh, to look your best you should dress according to your body shape. People come in all shapes, sizes and heights but there are some basic categories. Different people call them by different names, and sometimes you fit kind of in the middle of two different descriptions. I'd like to give you some general guidance.Some clothes look better on some body types than others for the simple reason of body shape. Have you ever tried on something with a friend that's the same size? Did it look better on her than you? Even if you are the same size on the rack, you may have very different body shapes.
First think about your height. Are you 5'2" or under? Then you fall into the petite category. Are you the average height of 5'5"? Then you=average. If you are taller than 5'8" you generally fall into the tall category when it comes to clothing.
A tip I've read that is pretty cool in helping you visualize your body shape, but can only be done if you have two people unfortunately is to get a big piece of poster paper and hang it on your wall. Grab a close friend and put on a form fitting (tight) outfit like a body suit, bathing suit, tights and tight tank, etc. Then stand straight and tall against the wall and have the other person trace you. Take down the piece of paper and put another one up and this time turn to the side. Have your friend trace your profile. With these two tracings you will be able to see where you carry your weight.
Once you see where your weight distribution is you can better classify your body type. An alternative way is to take your measurements. It is important to get accurate measurements, so it is best if you can have someone else do this for you. You will want to at least take your full bust, waist, and low hip measurements. You can take them on yourself using a mirror. Make sure you good form and don't suck in or tense up your muscles. When measuring yourself you will want to keep the tape measure straight and parallel to the floor. Don't let the measuring tape get crooked or twisted. Measure at the widest part, snugly. Not too tight or too loose. You want accurate measurements! Once you have your measurements you can see where you carry your weight better.
Using both of these methods will give you the best idea of your body shape. The tracing gives you a visual representation of the actual space your body is taking up, while the measurements give you concrete dimensions.
Let's start from the top. People who carry most of their weight in the top third of their body (shoulders, bust, waist) are usually called top heavy, broad shoulder or thick waisted. Sometimes these shapes are referred to as V-shaped (broad shoulders) apple shaped (full bust or full waist). Typically the lower torso and legs are quite small in comparison. Women who carry most of their weight in the bottom half of their bodies are often called pair shaped. This shape usually has slim top half (arms, bust, and even tummy) and heavier butt, hips, and thighs. This is an extremely common body shaped. If your bust and hip measurements (or tracings) are about equal and you have at least and 8" drop in circumference from bust to waist you are part of the so called body ideal of hourglass. This curvy shape is very balanced, but can range from looking pretty straight up and down (but waist goes in) to very, very curvy.
Of course there are gray areas and blends of body shapes. With weight gain or loss you may move from one shape to another. Whether you are petite, average or tall also makes your clothes fall differently. Just think of wearing a petite sized mini skirt if you are 5'10"...not only will it be super short on you, the buttons and details may look to small and imbalanced.