This is the order I have used on the last three worlds. It is not the fastest opening, but it is the one that survives an early neighbour.
- Timber camp 3, clay pit 3, iron mine 2
- Warehouse 3 — do this before troops, you will cap overnight otherwise
- Main building 5
- Barracks 1, then spears until you have 20
- Farm 4, then resources back up to 6/6/5
The instinct is to rush barracks and start producing. Resist it. Twenty spears in an undefended village is a gift to whoever finds you first; twenty spears behind a level 3 warehouse and a farm that can feed them is a village people skip.
Once you have 20 spears and 10 swords you are past the point where a casual raid is profitable, and you can start thinking about expansion.