I've done barely any quests but got four places with 10+ ppl each and 100+ defense, with about 4-6 advanced water purifiers each. i basically got stuck in this loop where i go to my biggest places collect all the water, then go trade like 400-600 purified waters at diamond city for expensive components. Then ill build up a new settlement all at once. Start it with water and a radio tower and 24 beds right off the bat. Then get 4ppl farming 24 total food, and get like 5-10 ppl working at scavenging stations.
My shits some brutal settlements if there's no body of water for advanced purifiers lol... No water means sleeping bags tightly packed in metal shacks, usually one choice of food, a buncha cheap ground pumps, and like 10 cheap turrets and im gone. If there's plenty of water ill do my best to wall everything off, use real beds, space everything nice, have a variety of crops, and set up a defense that looks nice and is more efficient
Anyway im stuck in a loop where im constantly getting water and selling and buying im level 24 and i swear probably 20 of those levels came from just settlement building and trading lol.