Pokémon Emerald Tips

Inherit a Nature Through Breeding
To do this you need an Everstone. To get one, search in Granite Cave for a lone rock on top of a plateau. Once you get an Everstone, let the a Ditto or a female Pokemon that you are breeding hold on to it. Once you receive and hatch the eggs, the offspring will have a 50% chance of inheriting the Nature from the Pokemon holding the Everstone.