Had a very nice, and a bit unusual, battle yesterday as the Teutonic Order. The Lithuanians invaded Lithuania after having been kicked out of there almost 50 years earlier (they had overgrown themselves like the AI usually does in the east). Now, I can't say that this was a very hard battle. This was pretty late in the game (1380ies something) so all my units were pretty teched up and I had a rather good (4 star) general. Adding to it, the enemy units were really crappy, but it still made up for a nice battle. The only thing that I had against me was being outnumbered 4:1 and that the enemy general was an eight-star one.
I had my army deployed like this:


The red is arbalesters, blue halberdiers and brown Teutonic Knights. The dark green is forests (the map was plainsinland since it was Lithuania so there were no height features). The black arrow is enemy approach, the purple is approach of enemy Horse Archers, Lithuanian Turcopoles and Lithuanian Cavalry. The orange arrows are the approach of enemy general (Lithuanian Cav.) and infantry (mostly Woodsmen, Lithuanian Infantry and Halberdiers).
This is a perfect example I think of a planned tactic that is pretty static, but that worked out perfectly. Since my troops were placed in the way they were and there were forests all over the map I didn't have much space to move (or well, I had a lot of space, but all of it was flatland), but the AI responded to my positioning just as I had hoped for.
The archery duel between arbs. and HAs/LTs was - not surprisingly - very easy and the enemy routed quickly. Once most of the horse archers were gone the main body of the AI army started moving, and it sent some Lithuanian Cavalry towards my arbs.
All of the enemy troops approaching were further weakened by my arbs. and the LC attacking them in particular. Once the cavalry reached my arbalesters I duly retreated them and let the enemy come into the forest were they were all slaughtered. Once most of the cavalry was gone I simply ordered all-out attack and mopped up the AI's infantry.