How to welcome a new roommate warmly
Meet the new roommate on arrival if you can. Show them the useful things first: keys, locks, trash, laundry, Wi-Fi, kitchen space, bathroom storage, and the house chat. A short tour is kinder than a long list of rules.
Leave a little room for the person to settle. Offer a meal or a walk to the store, but do not demand social energy on moving day. Moving is tiring even when it goes well.
Check in after the first week. Ask whether anything is unclear or not working. That simple question catches problems before they turn into impressions about the whole house.