The beginning of a still life

I began a simple still life recently and thought it would be worth posting about.  Using the shadow box I constructed out of black foam core I purchased a piece of wine colored fabric and laid it inside as a backdrop.  I then removed the mandible from a life-size plastic skull and placed it against the inner wall of the box so it gave me a three-quarter view.  I felt that it needed something else so I added a glass bottle that has a green tinge to it.  Almost immediately after drawing it in I realized the bottle wasn't working for me.  I plan to replace it with a smaller bottle standing straight up with colored liquid inside. I feel like that setup will make better use of the space and also add a little more interest.  Below is a shot of the painting so far.