At WordCamp Milwaukee 2014 I gave a talk on Building Better Widgets.
In this session I talked about how to design interesting and useful WordPress widgets. I covered designing for a wide range of widgets, exploring different widget designs, planning responsive widgets that scale well, thinking about animated and interactive widgets, and upgrading your widgets with plugins.
Download the slides to learn more and grab the links from my talk.
Update: Here is a video of my talk from WordCamp Milwaukee 2014: