Not the best, but I appreciate the relative intelligence of the secondary screeners at AMS on US-bound KLM flights (US carriers get a more thorough screening).

People meeting some physical criteria (thick-soled shoes, hats, lots of jewelry, etc.) are systematically pulled out of the line for an inspection, with complimentary pat-down.

While this alone won't help against savvy troublemakers, at least it has the merit of weeding out people who value their style more than other people's time, preventing them from holding up the line at the x-ray machines.