(1) Lots of heavy spearmen. Put them in a long line. Heard the enemy cavalry into a corner and kill them.
(2) Even better - lots of spearmen armed with javelins, like Thureophoroi and Thorakitai. Herd the enemy into a corner while throwing volleys of javelins at them and then kill them.
(3) Heavy spearmen plus slingers. Wear the enemy down with the slingers, and engage with the spearmen when they try to attack. You can also try archers but I've always found slingers more effective because their ammo lasts longer.
(4) Fight them in forests. Especially combined with (1) and (2) you will have a huge advantage.
(5) Fight them at bridges. Use phalangites (if you have them) or heavy spearmen to hold the bridge, and any sort of ranged units you like as support.
(6) Fight them in cities - preferably theirs.