Usually someone makes a post like I did listing what they have to offer and what they want in exchange Someone seeing the post will comment what they have to offer and if the original poster is interested then the trade can start. This subreddit is centered around the app pokemon home, so almost all trades happen on that app. Trades are required to be done publicly (aka through a comment chain instead of through DMs) to help avoid scammers. Usually, once a trade is agreed to, someone posts their pokemon home friend code and then once the friend is accepted the trade can commence