Save resources
To prevent allies from gaining your resources, do not build a market.
More Bases Advatnage
While this isn't exactly ground breaking, one should get used to building multiple bases. First build a main base fortified with two to three castles. Use a fast moving unit to scout the opposite side of the map as your base. After checking if the area is safe, send a villager to build a castle and build that base up.
All Your Base Hint:
Having more than one base will increase your odds of winning. Make sure to fortify your first base with at least two castles. Then send a fast moving unit to the opposite side of the map from your base. After you have checked the area and confirmed that it is safe, send a villager to build a castle at that location and fortify that base.
All Your Resources Hint:
When you are allies with others, do not build a market to avoid giving them resources.
Exploring With a Trade Cart:
Once in the Feudal age, build a Market and then a Trade Cart. Use the Trade Cart to safely explore your opponent's territory if your opponent is neutral.
Build Faster:
Continuously select the icon next to the percentage.
Use Barbarians:
Play in deathmatch mode and choose the Vikings. Instead of having Berserkers, they will have Barbarians.