The Top 5 Rules of Great Design.
I created these basic rules for the design of 3D content to assist new developers in gaining traction on their learning curve.
Rule #1 - ALWAYS ensure your design is square to the world axis.
Rule #2 - Always center your design to the world axis where x=0; y=0 and the base of your content is at z=0
Rule #3 - Clean-up your mesh (no overlapping polygons, no random floating vertices, smooth your surfaces, etc.)
Rule #4 - unwrap your UV and map your textures WITHOUT overlap. Make it simple for the end-user to re-texture the item.
Rule #5 - Use a naming configuration that is logical (especially with rigging)