I saw this for the Sims 3 and I realized no one made it for the Sims 4 so I thought I would start one. 1. Try an uncommon challenge, e.g. the decades challenge, nomad challenge, royal kingdom chal...
49. Have a YA sim buy a relatively cheap house. Renovate it as they get older instead of moving out. It might be fun to pass it down to their kids and have them do the same.