There's no surefire way to impress a book lover, but there are some things you can do to make a good impression. First, try to find out what kinds of books they like to read. If you can recommend a book that they might enjoy, they'll definitely be impressed. Secondly, show that you're well-read yourself by engaging in conversations about books. Finally, don't be afraid to express your own love of reading - book lovers are always happy to meet someone who shares their passion!