[R0b0t1]

Paying special attention to power distribution tends to help, along with encasing the product in something conductive. It's also really beneficial to have some kind of test equipment in house to get a general idea, think of it like having a debugger.

The first two options are somewhat expensive, the NRE for the power supply design isn't attractive to manager types and conductive coatings for plastic or a metal enclosure are not the cheapest options. But if you're dead set on compliance it's better to frontload the design costs instead of iterating 3 times before you get to market.