First off, set your inventory to private or friends-only for a few days to stop the automated spam bots from targeting you. When you're ready to list or sell, don't trust anyone in Discord or Steam DMs asking for "price checks" or "verification." If you're not sure about pricing, read https://todaynews.co.uk/2024/10/11/tf2-marketplace-guide-finding-the-best-deals-on-unusual-hats/ to understand how effect tiers work. I personally listed my rare unbox on DMarket because the trade goes through their automated system—no dealing with sketchy middlemen, and the buyer's funds are secured before the trade offer goes out.