I mostly play defense. Early on I concentrate on building up my economy. Therefore I put a cheap army on a hill. I've done well playing Italians with urban militia and militia sergents holding the slopes, with plain vanilla archers on the crests firing over their heads into the oncoming enemy. You do need a high valor general nearby to keep the boys on the line happy. As Byznatines (my favorite), I use the Byz Inf and Trebizond Archers in the same way with even better results. In fact, that is almost all I ever use. No Varangians, Kataphrakts, Byz Cav, etc. The Byz Inf and Treb servs me just fine.
On Offense, I usually attack with archers in front and Infantry bringing up the rear. I hardly ever use cavalry (too expesive, and I am too cheap).