Rewrite the caption, do not reuse it
Copying a caption written for a more formal or visual platform straight into Threads reads as stiff, since the format rewards a conversational voice. Rewrite the same underlying point as something closer to a real thought: shorter, plainer, more direct. It lands better than a polished repost.
Break a longer piece into a thread
An article, a long caption, or a video with a few distinct points can become a short thread on Threads, each post covering one point. This tends to work better than compressing everything into a single dense post, and it gives more individual moments for a reply to attach to.
Turn a single strong line into its own post
A single quote, statistic, or claim pulled out of a longer piece often performs better as its own short post than as one line buried inside a repost of the whole thing. It gives readers one specific, complete thought to react to.