Dresses that flounce at the bottom have added extra material to give a more pronounced A-line. This style accentuates your waist, making it appear smaller. While skirt-fillers can be bought at the store, you can easily make a tutu-like wrap right at home that adds volume to the bottom of your dress.
Measure the smallest part of your dress at the waist. Then measure the largest part of the dress along the bottom hem. These measurements will guide the amount of fabric you use when adding layers under the dress. The more you go beyond the length of the dress hem, the more material you're adding under the dress and the fuller it becomes.
Lay out the material you want to use. Tulle is a popular option because it's stiff and holds its shape well. Avoid materials that lie flat, like cotton and silk. The material should match the color and style of the dress.
Measure one side of the material to match the length of the bottom hem of the dress. This is the longer of the two measurements you made earlier. Depending on the size of the dress, add a few inches to this measurement. The additional material will fold when sewn under the dress, adding volume in its folds.
Measure along the other side of the material using the size of the dress's waist as your guide. Add a similar amount of inches to this side.
Turn the dress inside-out. Thread your needle with a long piece of thread. Secure the extra material at one corner to the waist portion of the dress, threading the needle through an existing hem rather than the outer material of the dress. This will prevent the seam from being seen. An ideal place to start is at the back of the dress by a zipper.
Wrap the material completely around the dress and secure the other corner directly next to the previous corner, making the two shorter ends of the extra material flush. The material now wraps the entire way around the waist of the dress. Secure the second corner with a stitch.
Sew another holding stitch half way around the waist. This ensures that you won't bunch more material on one side of the dress compared to the other. Bunch the material along the waist and continue to insert holding stitches until all of the material is securely held to the waist of the dress.
Hem the bottom part of the extra material along the bottom of the dress. Add more layers as you see fit with each extra layer adding more fullness to the bottom of the dress.