I was catching up on email and had the following persuasive element used by cafepress.com brought to my attention today. 

This is an awesome example for how to address concerns clothes buyers might have who are worried about both how a shirt might fit and how thick or thin a shirt is that they are buying. As someone who is ‘right on the cusp” between sizes, subtle changes can mean the difference between sizing up or sizing down. And whether an item tends to run large or run small or be true-to-size is incredibly helpful. Taking the time to think about how to convey such information is an indication of how they think about their customers and I’m sure it pays off in higher conversion rates and less product returns.