Common mistakes when posing armature 3D models include overstretching joints beyond natural limits, neglecting weight painting adjustments after posing, and ignoring bone hierarchy dependencies.
Overstretching (e.g., bending knees or elbows too far) breaks realism—real bodies can’t move that way. Skipping weight painting tweaks leads to uneven mesh deformation, like an arm bulging incorrectly when the elbow bends. Ignoring bone hierarchy (e.g., moving a hand without the forearm) causes messy limb positions, since parent bones control their children.
For beginners: Start with simple poses, use real references to avoid overstretching. Test mesh deformation as you work—tweak weight painting early to fix small issues fast.