Step 1: Get Your Garments.
This step takes some serendiptiy. Keep your eyes open for garments with great fabric. If they're too big or small, think about how else you can use it. If you're making a dress for competition, check on the rules and regulations of your organization. They may have requirements regarding skirt length, necklines, and sleeves.
I found these two dresses at my local charity thrift store. One is a silk chiffon with a bias silk lining which will become the sleeves, cape, head piece, and belt. That was $12.99. The other is a long A line skirt and a sleeveless top with individually hand sewn sequins. It was on clearance for $6.50 and will be the body of the dress. The tulle I got at a store close-out sale for $1/yard. I bought some clearance beads for under $10. Further embellishments, such as crystals and knotwork appliques, would most likely come in under $30.
Step 2: Mark the Skirt.
Start by marking evenly spaced lines on the inside of the skirt. These are your stitching lines to make the gathers. Do the same lines on the lining. This will help you later.
Step 3: Ruche the Skirt.
In either case, using a slippery thread, such as silk, will help you adjust the ruching later. When you come to a seam, make the stitches along one side so you don't have to gather the extra material.
Pull on the end of the stitches to gather up the material. This might be easier after you finish the lining so you don't gather too much or too little.
Step 4: Alter the Lining.
For dancing, I wanted to make the skirt more sturdy, so the ruching wouldn't pull out. Also, the ruching alone makes the skirt too bouncy. So I attached it to the lining along the same stitching lines.
The skirt was shortened, but the width didn't really change. This means that the lining under the shortened skirt is too narrow. Use the bottom half of the lining instead. Determine the length you need the lining to be, measure it up from the hem, and cut it off. No need to leave a seam allowance. Don't worry about the raw edges.
Step 5: Reattach Lining.
Mark the center front of lining. Put in a running stitch along the top edge of your lining piece. Pin it to the outside of the existing lining, butting it up to the waistband, between the skirt and lining. Pin the side seams to the side seams, and the center front to the center front. The back seam needs to be opened to accomodate the zipper, then pin it to the lining along the zipper on either side. Pull in the gathers and distribute them evenly in each quadrant. Pinning those four points first helps keep everything where it should be and not twisted.
Sew the new lining piece twice. This helps keep the gathers flat to reduce volume at the waistband and makes it more secure for supporting the weight of the skirt.
You now have three layers attached at the waist: the skirt, an outer lining, and an inner lining. (In this picture, the layers are arranged so you can see them. The linings don't really stick out the bottom of the skirt.)
Step 6: Secure the Ruching.
If you already pulled up the ruching in step three (as I did), you may have to let it out or pull it up more to where the skirt's just a little bit longer than the outer lining layer.
If you haven't pulled up the ruching yet, pull it up now so the skirt's just a little longer than the outer lining layer.
Then pin the ruching stitch lines to the corresponding lines (from step 2) on the outer lining layer. A running stich on the lining lines would let you do this by touch. Now sew the ruched skirt layer to the outer lining layer along the stiching lines. You can do this by hand and take a lot of time but have a softer look or you can do it by machine and have it secure and tighter. If you machine stitch here, use a tear-away topper to keep the presser foot from snagging and dragging the fabric. Scrap pattern paper is translucent enough to see the stich lines and will tear out if you pull sideways. Pin some of the excess lining out of the way or it might get caught in your stiches.
Step 7: Cut the Tulle.
Step 8: Make the Pettiskirt.
To shirr the tulle, run the long side of the strip through the sewing machine set on a long straight stitch. It will gather the fabric automatically. You don't have to sew the ends of the strips together, just chain piece, which is a quilting trick. When you finish one piece, butt the short edges and start on the next without cutting the thread. Do this to six 3.5" strips then use a long zigzag stitch to attach the shirred edge to the long edge of one of the 4.5" strips. The zigzag won't gather and makes it easier to catch the edges when you're going fast. Then shirr the other edge of the 4.5" strip. I wanted this less gathered, so I used a shorter stitch length. Do as many of these units as you need to get around the skirt.
Pin the strips evenly around the inner lining layer at the height you need to make it hang where you want. Then sew it on. Tulle can be scratchy. Sew it to the outside of the inner lining layer and make sure the shirred edge of the 3.5" strips is facing out.
You're done building the skirt.
Step 9: Make the Sleeves.
The silk dress I found was great for making flowy sleeves. This kind of a sleeve can be dramatic in performance, but may cause issues in competition where it's hard for the judges to see your arm position.
I dismantled the dress, separating the chiffon top layer from the charmeuse lining and cutting off the long straps. I cut the chiffon into right and left sides, one for each sleeve. I used french seams to sew the sleeve sides together, matching the other seams in the garment. French seams enclose the seam allowance and give a finished look on sheer fabrics. Straight stitch the pieces wrong sides together about a quarter inch from the edge. Trim close to the stiching, I used pinking sheers, but you can use regular scissors. Turn the garment inside out and press the seam closed. Then straight stitch again a quarter inch from the edge you just made, enclosing the raw edge of the fabric on the inside of the garment.
I hand stitched the sleeves onto the sequined top and added some extra ruching at the top to shorten them. When adding sleeves, remember to pin them to the top's shoulder and side seams then spread out the sleeve excess all the way around, pinning as you go. Then sew them in. If you just sew without pinning, they'll rotate with your stitching and be out of alignment.
Step 10: Make a Cape.
The neckline in front is a little low, too, and could be fixed with a piece of sheer fabric, possibly with some sequins or beads to pretty it up.
Step 11: Make the Head Piece.
I used a bridal buckram to make the head piece. It's covered with a piece of the lining fabric from the silk dress and has an old rhinestone choker sewn to it. Cut a strip of fabric wide enough to cover the front and back of the frame and have a little extra to fold in. Using a bias strip makes it easier to go around the curves. Sew down one edge with a running stitch then stretch the fabric up over the front of the frame and pin in place. Sew on any sew-on embellishment. This one is just whip stitched in place around each stone. Then fold down the fabric in the back of the frame, covering your stitches. Tuck in the extra at the bottom and whip stitch along the edge of the frame. A couple of loops attached to the inside would let you pin it to the hair while wearing it.
Step 12: Finish Up.
Have fun, challenge yourself, and let your imagination run!