/cgl/ - Cosplay & EGL

For reference this is the pattern drafting method I am emulating for my suit, where I have made a shitty polyester/spandex mockup (Cant use muslin because final fabric is moleskin spandex, which stretches), drawn the lines/panels for the bodysuit, and have cut it apart and added seam allowance.

What I am asking about construction wise is mostly the "trim", and if I should just topstitch it on or if If it is right sides together in the above image. Using Lightning's bodysuit is an easy example as the legs/hips of hers are very similar to mine.