Give tips on how to create attention getting headlines. Offer advice on keeping your headline short and concise. Give tips on using words that grab attention such as action words and verbs that are unique. Put forth information on how a question is more likely to be opened in an email subject line as opposed to a full out disclosure of what the email is about. Keep them guessing so that they are intrigued by your headline. Put in a benefit to them in order to get them to reply.