C Interfaces and Implementations: Techniques for Creating Reusable Software is the best thing I've seen on the topic, personally. http://www.amazon.com/Interfaces-Implementations-Techniques-...

I'd say "C programming: A modern approach" (K.N. King) should be a good candidate? Personally I like the book.

>Do you have any resources / books for writing modern C like this

No, sorry.

>is it all experiential from the trenches?

It's mostly about applying general principles of software construction like separation of concerns, encapsulation, robust interfaces, etc.

This link gets posted on HN a lot but I've found it useful:

http://c.learncodethehardway.org/book/

I'm interested in this too.