Take advantage of the email template designer or upload your own. There are also tools to segments lists and personalize emails with all your contact data. The A/X testing feature allows you to test up to ten different versions of your email before you decide which one stands out as the best. A campaign comparison tool pits your previous campaigns against the current one to give a complete picture.
I think this email also makes quite a brilliant use of responsive design. The colors are bright, and it's not too hard to scroll and click -- notice the CTAs are large enough for me to hit with my thumbs. Also, the mobile email actually has features that make sense for recipients who are on their mobile device. Check out the CTA at the bottom of the email, for example: The "Open Stitcher Radio" button prompts the app to open on your phone.
The primary cost of poorly crafted or mis-targeted emails is lost business opportunities, though in extreme cases it can damage a firm’s reputation as well. But the potential payoff for effective email marketing is substantial; email messages are more likely to be seen and acted upon by decision makers than online content, social media, or advertising.