What's one of the most influential lessons you learned in design school? For me it was "It's all about the transitions." Nailing the overall form of an object is important, but how you handle the transitions--the areas where different surfaces and materials meet--is where you can manifest the pro-level design considerations that separate good work from great work.
It's true of architecture too, of course. Everything from window flashing to door trim to interior molding is an opportunity to demonstrate excellence and a love of design.
How best to inculcate this in kids?
Lego! And while the most basic version of the interlocking blocks from Denmark have always been good at helping kids master the gross form, Legos now come in such a variety of detailed parts that Lego transitions themselves have practically become their own playground.
Lego expert Alice Finch--whose incredible work includes complicated compounds like Harry Potter's Hogwarts and Lord of the Rings' Rivendell--understands detailed Lego work well.
To help spread her knowledge she's written The LEGO Architecture Idea Book, which focuses heavily on design details: Columns, doors, windows, walls, towers, roofs, archways, trim, all of those areas where different surfaces meet. Here are some sample pages:
You can pick up a copy here, and you can see more of Finch's work here.