So, I just published a quick overview of Emmet on the Litmus blog. During the course of making the video and writing the post, I started wondering about all of the tools we use to design and develop emails. While I think Emmet is one of my favorites (it'd be hard to live without it), I'm curious: What tool has improved your workflow more than any other?

It can be something as simple as a pencil and paper, or as advanced as a complicated Grunt build process. Just share the tool, and how you use it, in the comments below.