For the Belle costume, I worked with Pattern Simplicity 2563. The pattern Simplicity 3943 would also work for a different look. I borrowed the collar from pattern Simplicity 5520. A piece about 30″ by 8.5″ cut on the bias. I bought a yard of sparkle fabric. I put the collar at the furthest to the lower hand corner of the yard fabric. Then I used the pattern tissue to cut up the remaining at 8.5″ high to make long bands for the lower skirt.
I had some yellow leftover fabric from making the Snow White dress. There was enough to do the top but I had to buy more for the skirt. The pattern said 2.5 yards which I thought we bought that much. I guessed wrong, I needed to go get more.
I pinned the swag on the skirt at about 8″ center back and each swag to the front was an inch higher, the center front was at 12″. Now feel free to adjust to suit the height of the child. I top stitched each swag down in a swag shape from each pin, plus the fabric is gathered/folded at each swag.
The skirt has (8) 15″ clear elastic gathered underneath. The one at the center back is obviously shorter. Starting at the seams and darts of the upper bodice and centered down the swags, stopping at the 2.5″ hem. The skirt pattern on this dress is super long. I used the 18m size skirt with the size 3T bodice. This was for my 3 year old daughter. I suggest using a dress size that fits her or measure your child to see which length works for you.