1. Keep Making Units

Constantly train Military Units. The only time when you should consider stopping Military Unit production is when you are saving up resource to research an expensive Upgrade, or to build an expensive Building, such as a Town Center, or a Fortress.

2. Keep Making Buildings

Many new players don't make enough Buildings. Having additional Military production Buildings allows you to reinforce much faster so that you can overwhelm your opponent and go for a victory. Have extra Wood stockpiled? Make some more Military Buildings!

3. Research Upgrades

Upgrades improve your Villagers' efficiency, your Military Units' combat effectiveness and benefit your civilization in various ways. Armory Upgrades are particularly important, as they make your Units much more cost-effective and pop-effective, resulting in a much higher quality army. Research them as soon as possible!