How do I make b-roll actually useful?

The Diagnosis

Bad b-roll is wallpaper: pretty shots laid over talking because a course said to add b-roll. Useful b-roll answers a question the viewer just silently asked. Every time you mention something, a 'what does that look like?' forms — and the cut that answers it instantly removes friction before it accumulates into an exit. That gives you three jobs to hire b-roll for: evidence (proving the claim you just made), process (showing the how while you say the what), and context (establishing where and when without narration). Then make the joins professional: let your voice trail across the cut so the story never resets, and use the mid-sentence cutaway deliberately — leaving a thought hanging while the visual answers it locks attention instead of losing it. If a b-roll shot answers no question, it's not b-roll. It's a delay with good lighting.