Responsive design was on the lips of many email designers. At Litmus, we love implementing responsive techniques and use a number of tricks to get our emails working beautifully on a variety of devices. We have our methods of targeting devices and screen sizes using CSS media queries, but what are yours?

Do you advocate working just on breakpoints for screen sizes? If so, what breakpoints do you normally use?

Or do you target specific devices using things like device-aspect-ratio, resolution, or orientation?