Hobbies And Interests
Economic Basics
Keep a balance between Towns and Castles within your territories. Towns are economic centers, and production should be geared toward buildings that produce social order and gold production. Castles contain the buildings and upgrades for most military and supplemental units, so emphasis should be placed toward the production, maintenance and upgrading of military units. Novice players make the mistake of trying to get every upgrade in every city, which quickly strains your economy to the point of bankruptcy.
Unique Units
Make effective use of your civilization's unique units, which in some cases are dependent on the terrain and local resources of your territories. For example, in the Middle Ages, English battle strategy should heavily utilize the enormous range and power of English longbowmen, which can shoot farther than any other ranged units in the game. Moorish cavalry is based on camels, rather than horses, which can tire out European horse units by racing them in desert climates.
Tactical Basics
Learn the principles of rock-paper-scissors. In real time combat, the battles are typically fought with some combination of infantry, cavalry and archers, with supplemental units, such as siege equipment. Infantry does the front line fighting, drawing the front of the battle, but can be broken by cavalry. Regular infantry should be supplemented with spearmen, who decimate cavalry. Archers can thin infantry, as well as outrun them if need be, due to lighter armor. Archers are especially devastating as defense in a siege. Cavalry can run down archers in the back lines to create openings to attack infantry from the rear in a pincer attack.
Crusades
Accept Crusade missions as soon as possible. This serves three purposes: Gaining favor with the Papal States (which makes other Catholic nations less likely to declare war), amassing a small fortune from capturing high population territories in the Holy Land and gaining a great deal of experience for young generals, particularly heirs.