Mine is similar to Tamur's, which is apt as I was playing his Britons game at the time.

I (well he) had Gaulish invaders in one of his provinces. 3 units of swordsmen, IIRC. He had an army that could easily destroy these measly invaders, but I knew that I wouldn't get any good traits if the odds were too high in my favour. Not having fought a battle with the Britons, I guessed at the best mix: 1 swordsmen, 1 warband, 1 Light Chariots, 1 General. I sent the chariots round the back of the Gauls, and the infantry round the front (on the campaign map). I attacked with the general, and the odds (thankfully) were reported to be close. (I believe it has to do with MP unit costs?)

Anyway, to cut a long story short(er), I advanced with my infantry from the front whilst closing with my chariots from the rear. Once I had them nicely sandwiched, I opened up with my light chariots. I maximised their effect by making the AI believe that my infantry were the main threat, and so they always had their backs to my chariots, which has the added benefit of making them uneasy by having enemy behind them. I concentrated on each unit individually until their morale started taking blows, then I concentrated exclusively on the captain's unit.

The second he died, I sent my infantry charging into the front of the enemy, whilst simultaneous closing my chariots, but only at a walking pace. As soon as the enemy starting thinking of a counter charge, I stopped and reversed my men. When the AI turned round to deal with the slowly moving chariots, I warcried my infantry and charged my men in for real. The AI desperately wheeled his forces around, but now I sent my chariots charging into too. They hit, as I had intended, almost simultaneously (the chariots first), and the Gauls broke immediately. I pulled my chariots out, having knocked down many men, to allow them to rout. I then pursued them, using my chariots to knock men down, and my infantry to slaughter them on the ground.

The result was a crushing victory, having killed every man without a single loss, and three traits for my previously one star general. I think he went up from 1 to 4 stars, with an extra 3 when attacking. Having read how ineffective British chariots were, I was happily surprised to see them work so well in a mixed army.