On a recent assignment for Nike I ran into the challenge of how deal with reflections on a large glass display case. The showcase was located in the front of the store near glass doors and could not be moved. I also encountered the issue of massive reflections from the front widows. I attempted to use a polarizing filter, which is sometimes the answer to reducing reflections, but the reflections were coming from several different angles.
The Solution: A large black back drop placed between the display case and the windows. The black paper eliminates the reflections. Next all I needed to do was cut a small hole in the backdrop to put the camera through.