What I like about doing BTLs is the freedom to explore and the challenge to be different.
A lot of accounts I've worked on in the Middle East have more budget for collaterals than ATLs. They'd rather have their materials out there, tangible, than to have thought-provoking print ads on the newspapers that end up as absorbent materials for somebody's dog's poop.
Here are concepts (some produced, most didn't) that were therapeutic. How Ace Hardware is therapeutic for men and how Bloomingdale's is for women.