Sometimes it is best to keep the look clean and simple. Uncluttered and tranquil.
Bringing the enclosure into the foreground draws the eye to the product first.
You will often find the product is located on the left or right of the image rather than the centre. This is to allow the client to use the image in a variety of ways. It can then be used on a double page spread without the risk of the product falling into the spine, but can also be cropped to fit a single page.
If, however you know the image will only feature on a single page, fun can be had to make a show-stopping centred product view!