A simple strategy about neighbors...

If you need goods: Tend your neighbor's crops and put your crops in the middle of your city for your neighbors to tend.

If you need coins: Tend their housing, water their crops, speed up the boats, tend businesses (slow), or cut down trees.

And an useful tip....

2 neighbors tended the same boat/crop!
- When a neighbor harvests your goods and an empty ship/ plot is left behind, you can refill that spot with a 1 hour good (like Shanghai shipping or Eggplants). When you accept help from the next neighbor, the spot will be ready to collect again!
- You might build a strategy around this were you leave a ship or crop ready for a little while and let your neighbors all tend that spot over and over while you just refill it.