Treat captions as alt text
Keyword-rich first 20 words in the caption. TikTok's search index reads them literally.
Hook with the query
'How to do X in Y' verbatim in the first spoken line. TikTok's search is improving but still benefits from literal matching.
On-screen text for searchers
Duplicate the spoken content in on-screen text. Search results show the text overlay in thumbnails — increases click-through.