Repetition is a Good Thing: Give your reader more than one opportunity to respond within the same email. Don't include only one link at the bottom of your email—your reader may never scroll down that far. When you send yourself a test email, make sure you can see links in your preview pane, which is the window in an email client that lets the reader "preview" an email before they open it.

Focus on What's HOT: The focus of your email should be on the offer or the content you think will be really exciting for your reader. Think to yourself, "What in my content is most compelling to most of the people on my email list?" If you've got two distinct audiences that might respond differently to different subject lines, segment your list and send them targeted campaigns. Also, don't confuse the reader with too many messages, unless you've set them up in a newsletter where each topic can be viewed and read concisely on its own.

Call-to-Action: When you plan your campaign or email, ask yourself "what do I want my reader to do? Buy now? Sign up now? Register for an event?" Make that message clear on the layout of the email. Also make sure each call-to-action is linked to where you want them to go.

Expirations Work: Create a sense of urgency around your promotion if you have one. For example, if you want your recipients to attend an event ask them to sign up by a specific date to guarantee their spot or receive a discount.