@monaloren screws can baked as normal maps later.
Like shown here for instance:
https://cgcookie.com/tutorial/workflow-for-creating-normal-map-decals-in-blender
Think of your lantern as being completely black (flat shaded, so no lighting information). That way you only see the contours. That should be your low poly model. Adding detail that doesn’t change the contour should be done with normal maps.
At least that is how I understand it, but I am pretty new to this style 😉
