Another thing I might suggest if you're looking to create a greater sense of depth is to put some back lighting in. Looking at your image I'm noting that most of it seems to be lit straight from the front (or the front light is wiping out the back light). Tweek around your front lights so they're coming in more from the sides... Maybe reduce their intensity a bit (or rather, reduce the intensity of the lights coming from the left or the right to get some shaping going on)... And then put a few lights in that are coming from behind. It cretes a sort of 'rim' around the objects and pulls them out of the background.