How do you make some lightweight joints for Wings / Custom Dummy? Click-in place ones?

Hi there.

I am looking into how to make joints for wings that click into place and can be manually moved by hand to a different pose.

Also I am looking into how to make a custom dummy that is pose-able with joints.

Any ideas on how I would make this dummy very easy to change (weight/size-wise) is also very helpful! My current idea is just stuffing it with plastic bags which I can remove or add to it. But it'd be a little difficult keeping them on unless I used tape and knifed it all the time, which isn't probably the best idea that's out there.

I have no idea what materials to use and what tools I need, or if there's pre-made things I can put together, a very detailed tutorial will help me a lot!