Be sure to conclude by noting how valuable this book acquisition will be. And provide multiple ways to be contacted, including email, phone number, and physical address.
A good book proposal shows how a book will add value for the publisher (or agent). If it adds value to your life, fine. But be sure to mention, somewhere in your conclusion, why it would be valuable for them as well. (Hint: if you are writing to a publisher, and you don't know everything you can about the publisher's mission, values, and agenda, your proposal is unlikely to succeed.)
Be courteous and patient, but persistent. And when your proposal is, as it probably will be, rejected (at least the first time), don't mope: learn. What does the publisher or agent know about your book market that you don't? (Probably a lot.) How can you change the book proposal -- and the book itself -- to resolve that problem?
Good luck, and happy proposing!