Here are the official moonstone city layout builds for non-water and water cities.
No water:
http://www.lou-fcp.co.uk/map.php?
map=L00000000000000000000000000000000D000000000000D000I0I0000000000I0I000N000000N000I0I0OGOFO0I0I00000GLGOFKF00000000OGOGOFOFO00000000OGOGOFOFO0000OGLG0FKFO0000OGOGOFOFOEEE00000OHOHOHOHOEJE00000HMHOHMHEEE000000OHOHO0EJE000000000EEE000000000000000EJE0
00000000000000EEE000000000000000E000000000000000
Water:
http://www.lou-fcp.co.uk/map.php?
map=W00000000000000000000000000000000D000000000000D000I0I0000000000I0I000N000000N000I0I0OHOHO0I0I00000HMHOHMH00000000OHOHOHOHO00000000OFOFOGOGO0000OFKF0GLGO0000OFOFOGOGO00000000OFOFOGOGO00000000FKFOGLG000000000OFOGOEEEEE000000EETTEE000000000000ET00TE
000000000000ET000000000000000EET0000000000000EE0
Obviously the key to make a moonstone city effective is to bring all of the four resources in line: wood/stone/iron/food.
What this necessitates is bringing iron to max, and customizing the rest to leave as little leftover as possible.
However, gold is different. You'll have gold from your other activities, so it is not necessary (nor is it feasible) to have gold = all the other resources. Clear?
Tips and tweaks:
1) Obviously if you have double lakes, you may be able to get away with one less farm. You can use this for an extra townhouse.
2) If you have wood/stone resource nodes, you can use those instead of a cottage, leaving an extra building or two for either iron production outside the inner wall or for townhouses/markets. This is highly recommended!
3) If you are sneaky and manage to build it in such a way that you have 2 extra buildings, stick a market and townhouse onto the water build.
I mean, that is the top of my head, but these tweaks give you an extra 5% at most. When finished, these moonstone towns will produce approximately 8 moonstones every 25 hours, provided you have the extra gold.
These cities require no defense. They will never be castled. If someone is plundering you, delete 3 townhouses and put up 3 hideouts. You'll just have to be very efficient in clicking the moonstone button every 3 hours.
RexTerra (Officer in Laureline World 5, Officer in Sausages World 9)