Benevolent LeaderG 20

I did this at the Taffington Boathouse

Ensure you have high Charisma (I had 10 when I did it)
* Recruit, or move 5 settlers to your location
* Build 3, lvl 3 clinics and assign 3 settlers to them
* Build 1, lvl 3 bar, and assign a settler to it
* Plant 6 mutafruit, assign the 4th settler to farming
* Build two water pumps
* Build enough defence (defence value should be higher than water + food)

Decorate/build the area until it becomes large (ie the size bar goes yellow)

Now the long haul,
1. Sleep for 24 hrs
2. Talk to each of the five settlers
3. Repeat above steps.

This last part took a couple of hours for the happiness to slowly climb to 100, but the entire time you need to stay at the settlement, as moving away can actually reduce happiness