Short vertical video rewards clarity. Start each clip with the most surprising fact, a strong visual, or a direct question, because viewers decide within seconds whether to keep watching. Keep the first frame readable without sound, since many people scroll with the volume off.
Repurpose one long story into a series rather than cutting a single trailer. A three-part explainer, a behind-the-scenes clip, and a short interview excerpt can each reach a different audience. Link every clip back to the full article or episode so the video supports the main site instead of competing with it.