I'm thankful daily for #Mastodon, but on my #wishlist is a default text file instance hosts can modify and auto-message new users with the "make an introduction with five to seven hashtagged topics or interests not on your profile."
I see so many #introductions from new users, but plainly very few told them that hashtagging their interests makes them searchable, findable, and connects followers to them that much faster.
That guidance helped me when I was new -- it'll help new users now too.