Model:

• Model properly sized in mm units
• Model has no hidden/frozen elements, no groups/linked objects
• No lights, cameras, helpers, layers, particle view
• All elements has 100/100/100 scale and correct normals
• No any modifiers in stack except of turbosmooth
• Elements properly named

Materials and maps:

• No missing textures
• No unnecessary maps in environment / background / unwrap modifier
• Material editor resetted, all paths striped
• Materials and textures properly named

General:

• No 3rd-party plugin used
• No ALC and CRP viruses
• Track View Controllers deleted