I would add:
Install all the screws for the add on items (rear view mirror, sun visors, over head lamp) before you install your headliner. It is easy to find the correct mounting locations by feeling trough the fabric for the screw heads. Then when you make your insision, it will be right on target.
Also, take pictures of the shoulder harness anchor bolt locations and the shoulder harness storage clip screw holes. Easier to know where these holes are now, then trying to hunt around for them once the headliner is installed. The sail panel is easy enough to locate correctly and then add the coat hook.