I made Sienna's doll a dress to match the girls' flower girl dresses, mostly because the doll had no clothes. It turned out kind of weird.
Then I made a quick t-shirt for the doll out of leftover fabric from my dress, by cutting a t-shirt shape out twice and sewing side and shoulder seams. It fits more like a dress and the neck is getting stretched out, but it looks way better.
Then I made some leggings out of leftover fabric from my practice dress. Quick leg seams and a waistband. Supposed to be pants, but leggings look better anyway under the supposed-to-be-a-shirt dress.