Because I planned on adding a princess seam, I decided to use the method I usually use for color blocking or weird design lines.Some versions have princess seams on her dress, some don’t. I initially planned on including the seam lines in my cosplay, but eventually decided against them to save on time. More seams always means more time when sewing!
Once the fitting is done, you can draw your design lines on while it’s on your body! This is the fun part. You may need a friend to help for the back, but I can usually make do with a mirror.Drawing these shapes while on the body has the advantage of you knowing how the shape will look when it’s on. If you do this in the flat, then there is a chance your design might warp or not look how you want!