This is one of my favorite female armor concepts on deviantART. The armor is a simple, clean design with good protection. It doesn't put a huge emphasis on the chest or butt like some other designs, and looks fairly comfortable to wear. As an art piece the shading is very nice and I really enjoy the amount of detail that you have put into this piece.
I saw from your comments that this was inspired from Mass Effect. I definitely see that, and think you did a great job! I see a lot of Kasumi in the one with the hood, but overall I think it's a really solid design.
Thank you ) There's more influence from Tali than Kasumi. When I was making this design I've played only 1st part of Mass Effect series and decided to avoid any material on ME to protect myself from spoilers. I've learned about Kasumi almost 2 years later after her introducing to the game )
love the hood, Though I must say I've made a few rough sketches, when I do draw armor. I have a problem, the armor around the stomach prevents them from being agile, they have to stand straight up. though I'm assuming the plate is able to bend.
This armour isn't rigid -- upper part can move over lower one though you can't practice yoga wearing it. If you have problems with armour design spend some time studying historical references and modern bullet-proof vests.
You can check this FZD youtube channel [link] for some useful tips and insights on concept-art (lots of videos on environments, vehicles, characters and some specific themes like portfolio preparation).
And sorry, for uninvited advice , make more sketches to get good final result. Sketching, searching for design and overall composition are more important than the final "render".