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