Depends on the armies of course, but along with using combined spearmen and crossbowmen, you can try to pin down large numbers of expensive knights by using terrain, and concentrating your efforts elsewhere. What I mean is, if you can work with the terrain, you can set things up so that you effectively neutralize a substantial portion of the enemy's army/points, so that you can bring up a disproportionate force elsewhere and win; early knights are more lightly armored but only moderately disordered in rough ground, late knights are severely disordered. This renders them basically useless against much cheaper crossbowmen.

One other route I've found extremely successful is with light cav and/or light skirms. This is important, I cannot emphasize this enough, but HEAVY CAV CANNOT CHARGE OUTSIDE OF 90 DEGREES.

So if you set up some type of skirmisher on their flanks, and another on their rear, they have to spend a whole turn just turning their unit. And once they do that, on your turn, you can literally just go to the other 6 squares they can't charge. With horse skirm, it's laughably easy.

If you're playing a muslim civ, that's a great route to go.