Want to do better at e-mail marketing? Sign up for e-mail from everybody else. Let all those retailers and service providers market to you — then pay attention to who does it well and how they do it. What subject lines catch your eye? How long or short is the copy? Do they use photos? What time of day do they send them out? How often? Do they include links to social media and websites? What kind of call to action do they use? You can learn a lot from paying a little attention.