Undergarments are a girls best friend!
seriously, find a good shapewear, it will smooth everything out and even bring you down a size. The one I've found and love has a build in (strapless) push up bra, and then goes all the way down to mid thigh. So I don't need to wear a slip or bra, just my shapewear.
Shape of the dress is key!
if you want to hide you tummy, make sure your dress has a shape, if its a straight dress on a curvy body the dress will hug your curves, and probably not in the way you wanted. So pick a dress that narrows in at the smallest part of you torso. And then flairs out at the waist.
Distract they "eye"!
Even though you don't think you have a big chest, fake it. Get a push up bra, or one that just looks really great on you. Then choose a dress with a V-neck. (if you feel the V is a little too deep, just use a safety pin on the inside to bring it up an inch) By showing off with a V-neck your elongating the neck and making drawing the attention away from your middle.
Add Bling!
Even if it isn't big bling, make sure to wear a necklace, earrings, bracelets. Necklaces and earrings help with the idea of bring the "eye" up, just like the V-neck. Plus if you have cute jewelry more people with be looking at that, then your curves.
Show some skin!
If your like me might not like showing off you arms, but I am fine with my legs, so I always wear a short formal jacket with my dresses. But I make sure to get a dress that ends right around my knees. Because I'm really short, having a shorter dress and showing off my legs actually makes me look taller, along with wearing heels ;) But if you don't like your legs, and feel comfortable with your arms, pick a longer dress that's a halter top or sleeveless.
Phew, lol Those are the biggest things I can think of :D I hope that helps you a bit!
Ok so here is a great example of my favorite style dress!
The sash type fabric at the waist, makes her look smaller by faking a little waist.
The V-neck makes her torso look taller and thinner.
See how the dress has lots of fabric bunched at the waist and then flows out and away, that hides the tummy.
And the length is perfect! Just above the knee, makes her look taller which in turn makes her look thinner and shows off her legs, and takes away from the belly. Which is what its all about! lol :D If she had on some great bracelets and a necklace, she'd be set!
Dresses that looks a bit wrapped around the bust will make your chest look bigger and take attention away from your stomach.
I have a really pretty rose print dress from Talbots that made me look a full dress size smaller for my older brother's wedding.
Empire line, any dress with the waist right under the boobs. Then large flared skirts. Also surprisingly pencil skirts if well fitted. The curvy shape is good for them, it just tends to be that we buy the wrong sizes.
I know people that have this problem, and something easy to do is wear the elastiband skirts that go obove your waist. If the dress is full (or skirt) Your tummy won't even be noticed:)
Peplum tops are good as well.