In this cinematic, I was responsible for the hair simulations along with dog tags, and holster. Also, rigging SKX's mouth was challenging to get it to look good. I added 2 extra joints to the mouth to get better results.

About the dynamic simulations, the process is to create a joint chain of at least 2 joints. Then I use spline IK on the chain, and make the curve a dynamic curve. With that, I can edit settings on the curve, like weight and drag and so on. I can also make proxy objects to help keep the dynamics objects penetrating geometry that I dont want it to. Once I am happy with the settings(which only need to be set up once) I can load any animation onto the character, bake down those joint chains, and then delete all the physics info so that the animation can go into game with the sims still on there.

This method makes it very fast to get great secondary motion in seconds and takes all the time and effort off the animators.