Since most of you voted that your stomach is the body part you feel the least comfortable with, I will start there.
First of all, I think it's important to note that there isn't one body type that is good/bad. I think many of us have a skewed perception on what we should look like anyhow (I know I do). And while it's important to eat well and exercise when possible, we're not all going to be a size zero. Nor should we be. Having a bit extra around the middle isn't necessarily a bad thing; it just means your body is changing, becoming more womanly. The most important style tip to those who are middle figured is to not accentuate said voluptuousness. Here are some options:
When selecting a dress, it is important to look at its shape in reference to your shape. If you tend to carry your weight in your mid-section, select dresses that have an empire waist. This will create a very feminine shape, without accentuating the stomach. Black is always a very classy and slimming color, but don't be afraid to branch out. Just stay away from large, loud prints, as they tend to appear boxy.
When considering what tops will be most flattering on your body, you can apply some of the dress rules I have mentioned above. Tunic tops, empire waists and a-line shapes are your best bet. Another option is to buy a belted top, or to layer a belt over a more structured top (like a button up blouse) in order to flatten your midsection. Stay away from super skinny belts as they tend to create the opposite effect.
[A brief side note about outerwear: stray from cropped jackets or cardigans and bomber jackets, as they tend to hit (and thus highlight) the very portion of your body you want to disguise... do wear longer coats, jackets and blazers that are at least long enough to graze your bum.]
The great thing about being middle figured is the myriad of stomach-flattening options there are out there. Tights (especially with a control top) are an excellent way to flatten the belly, and are especially effective when worn under a capacious dress or tunic. High-waisted pencil skirts are also an amazing option because they are timeless, fashionable and do an incredible job of reining in that unwanted belly mass. They are also perfect because they work best with a-lined tops and more voluminous tops, so your body is flattered in multiple ways. Stick with a straight cut pencil skirt, with a length to at least the knee, depending on your height. Concerning jeans, always opt for a higher rise jean (I'm not a big fan of the super high-waisted jeans out there, but go for it if you like that look) because the lower the rise, the more your stomach will hang over.
Well there you have it. Just a few tips and tricks to conceal the belly. Now go out there and own that figure!