For social media, I post an excerpt from my blog posts on social media, with a link pointing back to that post on my website.
Though social media platforms prefer you don’t do this, because they want to keep you on their site, I want to get people to my site. That’s what is most important to me. That’s why I tease the post on social media and send them to my site to read the full piece.
I don’t think it’s a good idea to repeat the whole post on social media, and it’s too time-consuming to write a new post just for social media.