As you might have seen in the previous post, using key frames to rig a character is not such a great idea unless and until you have really good grip with making the transitions between different poses look non-robotic. One has to have a really good knowledge on the body dynamics to make it look natural.
And it is quite tedious to make the body language look natural by manual animation. So , what most of the CG movies use now is Motion Capture. They record motion of actors in controlled noise-less conditions and use this recorded data to move characters. Even the big video game companies use this technology.
This makes the process of animation much simpler. However, it is very costly to record such data. Everything comes for a price.
However, there is a huge database of motion capture data available online that one could use to import and apply to a character. Here is a wonderful blog that helped to figure out how to use the motioncapture data that was available online to animate a character. Basically, one could use the mocap data in the form of fbx to animate a character in any game engine.
I have used MoCap data from CMG database and filtered them to check in Unity how the result is.
And This is how it looked in the game scene. I have just wanted to have a idle motion while waiting for the game to begin, in a galaxy far far away.