...another question.....how do you max out EVs aside from using stat enhancers?
Battle, battle, battle. They're not called "Effort Value" for nothing. Each kind of pokémon awards you a certain number of effort points for beating it. Whismur, for example, gives you a single HP effort point, while Duskull gives you two: one in Defense and one in Special Defense. Once you've reached your limit with supplements, battle the enemies that raise your EVs the way you want them raised. You'll know you're done raising a pokémon's EVs when the woman standing next to Slateport Market's Energy Guru gives the pokémon an Effort Ribbon as a prize.