Tips for writing an appreciative (fan) letter
As composed for the author’s own use, because she worries a great deal. She makes no warranty as to their wisdom or universality.
1. Be polite. Addressing the e-mail “Dear Ms. Author:” or “Ms. Author—” and signing it “Sincerely, Me McMyself” may seem extremely formal, but it denotes respect and gives the recipient a familiar format to understand and engage with the contents.
2. Be specific. If you can, pick one or two things you really enjoyed about the story and mention them: “The main character seemed very real,” or “The plot drew me along from the very first page” or what-have-you. Being imaginative and neurotic creatures, writers often are unsure of their own strengths.
3. Be brief. This is, after all, a stranger. (If it isn’t, why don’t you know how to e-mail them already?) They may be busy, perhaps even writing something else you will enjoy. Say your piece and get out of their inbox.
Those are all my rules for myself at present. These were composed for sending appreciative e-mails to authors of stories in magazines (total appreciative e-mails sent: ONE. Such expertise!) and may not apply in other situations (I sent a paper letter to Lloyd Alexander once, thanking him for multiple books reread across my lifetime, and you better bet it was longer and more effusive.) If you wonder why you would want to write an appreciative e-mail to an author at all, this is why.