I found this summery dress at JCrew a few months ago, and loved the colors. It felt so preppy and nautical, I imagined it as the perfect casual summer dress. I tried it on and it just fit ...weird. Like it was supposed to be slouchy, but the waist hit me in a bad spot (probably because I'm 6 ft tall), and the stripes made me look fat. I bought it anyway because it was $20 on clearance, and let's be honest, I'm a sucker for a good deal. I tried to adjust the straps to make it hang differently, tried a belt to bring in the waist, but it never looked right. I asked my husband if it was horrible, and his response was, "Well, it doesn't look great..."
So that sealed this not-so-flattering dress's fate.
This concept could be used on lots of different types of dresses, just look for ones with a waistband, that would look good with a drawstring. My mom did a similar refashion with a strapless maxi-dress that she turned into a maxi skirt.
First stare at your dress and make a plan. This is very important. Every dress is made a little differently, so you will need to inspect it to see what your options are. My dress has an elastic waistband, sealed in a casing. My plan was to cut off the top of the dress, above the waistband. Luckily since its knit fabric, it doesn't need to be hemmed, it would look fine with a raw edge. But since the elastic wasn't tight enough, I had to figure out how to cinch it up. I thought about using ribbon or some kind of cording, but it wasn't the look I wanted. I could have used the fabric from the top and sewn a drawstring, but it seemed like too much work. And then I realized I could use the straps as a drawstring.
So, start by turning your dress inside out. Make sure you know where to cut, and then do it. Its scary, but just make sure you're cutting in the right place. Take a deep breath...
You could use ribbon or whatever else you want for the drawstring. If your straps are like mine and you want to use them, first cut off the slider thing. Stare at it first to make sure that you cut it in the right spot.
Do the same thing to the other strap, and then pull the slider thingys off.
Now, my straps weren't long enough to use on their own as the drawstring, and then I realized that I could cut the finished edge off with the straps and it would make one long string. So I carefully cut just below the seam, all the way around the top of the dress.
Clean up the string, cut off any tags or loops.
Now that we've go the string, time to fish it through the waistband. Cut a tiny slit in the front center of the waistband.
And then attach a safety pin to the end of the string, and fish it through the slit, and then all the way around the waistband, til it comes out the slit again.