I've been performing in an Irish Dance troupe for a few years and wanted my own twirly dress with sparkles and pleats. This is the solo dress I made for myself. The designs are based on the Turoe Stone in County Galway, Ireland. The dress can be seen in performance here: http://www.flyingirish.com/Appearances.htm
This is one of the first garments I made so there are lots of fixed mistakes, but it's ok, you can't see them from the audience. I dismantled a long skirt and a sheath dress for the body of the dress, keeping the neckline and zipper. I used a pattern to get the seams right over the bust. I wear this with a long sleeved shirt underneath.
I didn't make a dress diary, so instead I'm posting instructions and a model, which I hope will help you understand the construction.
Step 1: Make a mock-up.
Step 2: Appliques
Step 3: Transfer the designs to fabric.
Step 4: Attach the two layers.
If you just cut out the shapes like this, you'll fight to keep the edges together. I used matching fabric paint (not matching here) to trace the lines. This basically glued the two layers together and gave me an easy line to follow when cutting out the shapes. You could probably use glue, or a hot knife if you're using fabric that melts, but I haven't tested it.
Step 5: Apply the appliques.
Since these appliques go right to the edge of the dress, they had to be in place before attaching the lining and the pleats. I'll cover those steps next using a small mock-up.
Step 6: Assemble the dress.
Green: Dress front.
Yellow: Dress back and sides.
Fuschia: Lining front, back and sides.
Pink: Pleat front.
Purple: Pleat lining.
Step 7: Build the pleats.
The pleats are built before they are attached to the dress. Join the front and lining at the hem, right sides together. Add a strip of plastic horsehair braid along the hem, fold the front and lining together right side out, and top stitch to hold the horsehair braid in place. Fold in the sides, closing the pleat, and edge stich. Be sure to stitch the fold through the horsehair braid.
All this will help the pleat keep its shape and fold back into the skirt after a kick. It also gives it a finished look and lets the front and lining act as a single piece. A stiffer dress would use a different strategy here.
There is also a picture of the real dress here. Note that the hem line of the closed pleat has to match the curve of the dress hem, otherwise the corners will stick out below the dress hem. That's why there's a ruffle at the bottom of this dress. It just happens to also look good.
Step 8: Attach pleats to dress front.
Sew dress front and lining front right sides together at the hem. Add a strip of plastic hoarshair braid to the lining at the hem. Make a sandwich of the dress front and pleat front right sides together, and the dress lining front and pleat lining right sides together. Sew this seam up to the top of the pleat. Repeat with the other pleat. It will look like an inside-out pocket with the pleats stuffed inside. The horsehair braid keeps the front of the dress open so you can see the designs.
Step 9: Attach pleats to dress sides.
Repeat the last step to attach the pleats to the dress sides. Turn the dress so you can make the sandwich from the dress sides and pleat front right sides together, and the dress side lining and pleat lining right sides together. Sew this seam up to the top of the pleat.
This time, I didn't use the horsehair braid because the appliques provide enough stiffness for the back of the dress.
Step 10: Sew front and back together.
Turn the dress so it's inside out. Sew the dress front and dress side right sides together. Continue this seam down past the pleat. I had to do this part by hand; I couldn't get the machine in there. You want the pleat to come from the inside of the dress. If you start it right at the top of the opening, it doesn't lay right.
Step 11: Sew lining together.
Step 12: Attach the lining to the dress.
This is the main reason why I would do a two piece next time. That way, the pleat can be anchored to the waistband.