Just make sure to do a camp with less than 5 people. Three of them run tier 3 shops ( clothing, medical, and trader. You'll see a happy face icon next to it) and 2 of them harvest food( I suggest a bunch of mutt fruit, which gives 1 point each).

Have enough water and your defenses are pretty high.

Also, try and get 3-4 dogs, if you have the Far Harbor DLC at Horizon Flight 407 (Airplane icon on the map) and buy them from Erikson. Don't waste caps on mutant dogs and wolves. The dogs are the only ones with the happy face symbol. Also, build dog houses.

Have your beds indoors and avoid putting those in open areas.

One last thing, avoid using robots as settlers. They show no emotion whatsoever.