What I do: Send occasional reviewer-only newsletters with links to review copies.
What you do:
1) Have a good faith intent to review the books you receive, at your own blog or at multiple retailers.
2) Include the text "(free review copy)" at the end of retailer reviews.
3) Let me know where the book was reviewed; no need to send the text or details unless you choose.
PS: It's important to open the emails even if the timing isn't good for you to review. This list will be carefully managed.
What I won't do: Check up on individual reviews, police reviews, look over your shoulder, make things awkward. No one wants that! This is an honor system.