Checklist for Prepping a Model for Texture Painting

My apologies - I had forgotten to add it to the description. Thanks for the catch! Here it is:

• Apply modifiers that affect the UV layout.
• Convert non-mesh objects to meshes if you want to include them in your unwrap. 
• Combine your asset into one object if practical.
• Name your objects and organize the Outliner.
• Assign materials based on what parts of the asset can share the same set of textures. 
• Make sure you finish any rigging before unwrapping. 
• UV unwrap and use a default checker texture to make sure there is no stretching. 
• Pack your UV islands with at least [texture resolution / 128] pixels of padding.