How do you make a thread on Mastodon?

Pretty much the same way as on Twitter, with one difference. You compose the first post, publish it, then reply to it, then reply to it again, and so on. But there's one difference. If the first post is Public, you can make all the others Unlisted. This way, people can follow the thread by clicking on the first post, but their timeline isn't clogged up with all of the other posts.

[A short thread]

#FediTip #help

If you use the Metatext app, you can create a thread much more easily. Compose the first post and then, before you publish it, tap on the + button at the bottom right of the edit box and it will start a new, threaded post. Note: when you finally publish the entire thread, it might look on your timeline as if some of the posts are out of order. But go to your Profile and you should see them in the right order.
@garry (is there a non-IOS app that works like that?)