Princess Pam-attitude
Ok so here is a great example of my favorite style dress!
<a href="http://www.flickr.com/photos/pascailpamela/7161264316/" title="dress1 by pamela pascali, on Flickr"><img src="http://farm8.staticflickr.com/7080/7161264316_e3fd5f5cc8.jpg" width="246" height="300" alt="dress1"></a>
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 
If she had on some great bracelets and a necklace, she'd be set!
Posts by Princess Pam-attitude
Ahh I know what your mean, except I never had kids, lol. So I don't have a decent excuse for my belly XD
Anyway Here are some tips I've found-
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 I hope that helps you a bit!
Have you ever made those fabric blossoms that are all messy, they are usually made of chiffon or tulle? Or have you seen them at the stores? Thats what I thought of when I saw the skirt part of the dress. Not that I thought it looked like it had blossoms on it, but the way you make the pieces that make up the blossom, individualy they look messy and just like cruppled together fabric.
Anyway I thought that if you made the base layer for the skirt, and then made individual bunched/rouched pieces, you could then play with the placement and when you got the look you wanted hand sew them into place. After you had the desired ammount on you could go back though and add the longer pieces, that look like long thin feathers maybe, or w/e.
I would deffinetly do it in layers though, the base layer of skirt form, then messy bunched fabric, then the longer bits.
If you have no idea what Im'm talking about with the fabric blossoms PM me and Ill send you an ebook I have on how to make them and you can get an idea for what I mean XD
Best of luck!!
When I saw the picks they look like they have elastic on the inside of the "condom" and either a clip that hooks onto the back of the shoe, or a really stiff material on the inside to keep the top part sitting up straight... hrm