Instead of starting to draw / sketch your new UI, this article suggests ‘priority guides’, basically a ordered list of boxes with actual content as a basis for your design. The authors suggest that sketching an interface without prioritizing content first may, among other things, lead to premature design decisions. Hence, (for the tl;dr’ers) try sorting the (actual!) required content first, for mobile, and then try to fit it into a nice design. (but please do read the article)