When I was making dresses for my dd's they wanted "twirly" ones- so I would use a simple bodice pattern from an easy commercial pattern, and make a big skirt to attach. I'd hold the fabric up to my dc to see how long to make the skirt, add a couple inches for hemming and seam allowance and then cut 2 big rectangles.
I'd stitch those rectangles together to make one really loooong rectangle, and then gather one long end (where it would attach to the bodice.) I'd sew the skirt on to the bodice and then hem the bottom. You can also attach another band of different fabric at the bottom for contrast. I'll have to see if I can find any pictures of the ones I've done, they are pretty cute. And easy since most of it is all straight lines.
I could do two in a day easily. (Oh, I hate {and suck at!} working with patterns, so it was way less pinning, cutting, matching, pinning, sewing for me to make these big twirly skirts than the aline or whatever was in the pattern originally.) YMMV