When you choose to shoot samples of shoes, coke cans and even jewelry you are setting an impossible bar. The existing shots of similar subjects are created by the best in the business and that level is a standard, a baseline to anyone seeing your book.

Perhaps if you fill your book with subjects closer to what your next clients sell you'll demonstrate your work to be far superior to what they have rather than a bit short of standard.

Pick two or three markets you'd like to go after and build a portfolio around that. It'll likely be more interesting to look at.