Team Work

Team Work

Certain civs go well together, like the Celts and Persians, because the
Celts need wood but don't need food, and the Persians need food, but
don't need wood. As a result, these two teams can trade each other the
resources they don't need and can greatly help their ally. Other teams
like this are:
Mongols and Persians
Britons and Persians
Mayans, Persians, and Celts
You get the idea

Another tip is to do double team attacks, in 2v2, quickly double
rushing one enemy so you can eliminate him. This means that one person
on the double rush team will be open for an attack, but this is
nullified by the fact that you won't take as much abuse as the person
double rushed. Another way to nullify the attack is by clumping, this
way the enemy can only get into your base with siege.