Since you posted the Samus photo I have a question that I've kind of been too awkward to ask until now :P With costumes that are so form-fitting like Samus, Mara Jade, and Asuka, what do you wear underneath so that lines don't show through?
This is a GREAT question because I wish someone would have told me what to wear under my bodysuits years ago.
Shapewear is a wonderful tool and I recommend it to people of all sizes. Not only does this prevent panty lines from showing, it smooths out all your shapes and keeps potential food babies in check. The “wear your own bra” style is extra great and versatile. Body suits tend to compress your chest, so lots of cosplayers (including me) choose to wear padded push-up bras with them to balance the figure and create a more flattering silhouette.
The shapewear acts like a lining that can be washed frequently, so that the whole bodysuit doesn’t have to be. Unless you’re sweating A LOT or something, the bodysuit stays relatively clean.
Here’s the brand/style I actually use: https://www.amazon.com/gp/product/B00284B5G4/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
On a related note, here is a very important bodysuit undergarment PSA that can’t be shared enough: If you have a penis and you’re wearing a bodysuit, PLEASE wear a dance belt for the love of god. No one wants to see the sad outline of your flaccid wiener. A dance belt is designed to keep your dick under wraps. Google it if you need to.
Good luck with your bodysuit adventures.