I can't 100% help with the pattern part but I do know simplicity sells a ridiculous amount of dress patterns that you could use the top from one and the bottom for the other. I think I have two that would work but I'd have to dig through them and tell you which ones.
Personally for the designs, I would probably paint them on. It doesn't look like a second layer, nor like embroidery to me. That's just my personal preference though. :3
- No cons in the near future
- 'Raver' Versions of the original 4 starter Pokemon
- Floral Fallal Yuna (Final Fantasy X-2)