Talk to the candidates about what they’ve done. Ask them about their most impressive projects and biggest wins. Specifically, ask them about how they spend their time during an average day, and what they got done in the last month. Go deep in a specific area and ask about what the candidate actually did—it’s easy to take credit for a successful... See more
To the extent that we can give a brief answer to the question of where novel ideas come from, it's curiosity. That's what people are usually feeling before having them.