In our previous example, we posed our characters as one unit each. Using a LEGO minifig or typical action figure/doll will give you a few more parts to work with and you can then explore arm moves, head turns, and walking.
If you use clay, wire, or a jointed figure with a high degree of freedom, you can do more elaborate posing of the character itself. This is a great time to study how things move in real life!
Here's a test I did using a StickyBones posing figure. You can see how the emphasis here isn't on moving the character around a set as much as it is rotating the character's joints in place to convey a certain pose or attitude.
This is a stop motion armature that uses hinge joints, ball joints, and wire fingers. It's highly poseable, yet holds poses well. Typically, a foam puppet is built around this type of armature.
One thing you'll notice with larger poseable characters is that is can become important to tie down one or both feet to prevent the character from falling over in more extreme poses! Some armatures have threaded or smooth holes for attaching them to the set with tie down screws. Other's may have magnets. Here you can see my straps forward shrug animation test where the feet are attached to the metal base plate with magnets to prevent the character from falling over (the straps aren't actually supporting the figure much, it's mostly the foot magnet strength).
In some cases, a character simply cannot hold a pose without extra help. Jumping into the air, for example, is impossible without some kind of support rigging. Here you can see an animation done using a flying rig, as well as the shot after roughly matting out the rig using post-production software, in this case Premiere Pro.
As you can imagine, it's possible to layer on more and more layers of detail and complexity as we consider facial animation, secondary animation of clothing and props, and so on! With practice, it's possible to achieve incredibly complex, dynamic, nuanced, and emotional performances with stop motion.