Have no pointers to videos covering subject precisely unfortunately, however…
Imagine you have a human-like armature: head, torso, 2 hands, 2 legs, 6 bones in total. You can attach Cubes to the individual bones by Parenting so that one bone drives one cube object.
Now, there is no secret how cube can be unwrapped and textured, methinks. If you do texture ‘full body’ in the example above you end up with at least 4 texture images: head, torso, one hand and one leg- you reuse same hand and leg images for the left and right, ofc.
Imagine you combine all 4 images into one big image using photo editing software. You can place UV unwraps for Cubes on this big image and make changes in texture settings for each cube so that instead of using separate images big one is used.
That’s it in a short.
Texture Atlas addon is advertised and briefly described last time in G.Alexandrov’s YT channel here afaik.
Blender’s wiki page for addon - https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/UV/TextureAtlas