Here's my battle plan. Proven, for experienced players only. --Location--
When I start out, I position myself away from my enemies. Far out. I usually pick a spot near the edge of the map, or inside of an easily defended area (e.g. the cliffs seen in some maps). I also make sure gold veins and lumber are close at hand. Quite close at that.
--Build Up--
After building my Great Tree, I follow this with Golden Sprouts and Ancient Forests to being to build up my resources. I move on to tree houses shortly to build up food. After beginning to build up resources, I build every type of unit housing in close proximity. Setting spawn points for them in one area where no buildings are. I continue to build resources gathering places, but unit buildup is key to my edge over others. By the time I'm ready to assualt, I have many many units at my disposal. While continuing to build up both resources and forces, I began to build protecting forests around my kingdom. Once in place, you should have about two walls off these forests in front of your main buildings. Forces can travel through without gates so it's safe to surround your whole area. **EDIT* Move your barracks close to the front lines and circle them in forests for quick troop buildup and good troop movement.
--Atacking--
When attacking, I begin to take over the closest enemy, as not to allow myself to be teamed while on a far out expedtionary assualt with one of there allies left unchecked close to me. Now, as you send your units to the target, you should begin building forward operating bases. I continue to build protecting forests along a route to my enemy, building unit stations along the way. It offers easy replacements for destroyed units and a fast attack scheme to overwhelm your enemy.
--Defending--
When defending, I usually keep it simple. Encase my kingdom in a massive dome of protecting forests. Along with that, having ready forces to go out and destroy the opposition. My key advantage in defending is to, once a building is destroyed, as quickly as possible replace it. My opponenets never use this strategy and just let there kingdoms fall. That is your ultimate destruction. So keep replacing as much as you can. Simple, yet effective.