movement in joints? How to?

Hello guys,

So I am working on a half suit and have a question. I know it has something to do with like darts but completely confused as to where and how to measure the pattern for it. Also what is the best way do this with less creases. I know there i gonna be with stuff like this but it would be awesome to be able to make it to move but not show quite as much

If any of you guys have pictures and/or advice I would great appreciated.
Thanks!
Bayru