One topic I come back to is the tension between creativity and productivity. I find it interesting in general, but also because web designers site at their intersections. Both creativity and productivity play a role in our success.
One topic I haven’t yet covered where responsive design is concerned is how to work with data tables. Part of the reason is that I haven’t had to work with them much. For whatever reason my clients haven’t needed tables beyond very simple ones where a bit of flexibility was enough to make them work responsively.
The easiest way to rearrange a design’s layout for different devices and conditions is simply to drop one column below another when space no longer allows them to sit side by side. It may be easiest, but it’s hardly the best approach.