How I love love love balloon dresses! You do two?? Great couse here you can see how to make one out of a oversided shirt and a tanktop.
Great for this summer!
do the same as the up part. distribute the fabric equally and pin it.
Sew it on. this wil be harder to do because you'll have 3 layers to pull.
If you pulling is not enough to get the pink on the black equally than wrinkle the pink during the sewing. Try to estimate this soon because you can't wrinkle at the last time everything.