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.

Maybe you could provide some of your favorite resources to those things, then?

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.