Walking around with it in the party is good, making it gain levels, giving it protein, iron etc increases it as well. Also in the underground there is a duo of hairdressers below Goldenrod who increase the selected pokemons happiness. A soothe bell can also be given to a Pokemon to hold which doubles all the happiness increases for each method.
The Pokemon that will evolve through full happiness or maximum happiness are Cleffa, Igglybuff, Pichu, Riolu, Togepi, Golbat, Chansey, Azurill and Budew.
I assume you're talking about full happiness. Variety of ways to do this, really.In Pokemon, there is a maximum happiness level of 255 for ANY single Pokemon. Certian things boost happiness, and some lower it. A full article on it is here:www.psypokes.com/lab/happiness.php
you have to have a pokemon at full happiness. if it was KOd in a battle, it loses happiness points
You have to evolve BUNEARY with full happiness.
Chingling will only evolve into Chimeco if it's happiness is full at night time.
Golbat evolves into Crobat in Pokemon Emerald by full happiness.
Level it up when it its happiness is full
In salport city there is a woman looking at a picture in the Pokemon fanclub. Make sure the first Pokemon in your party has full happiness's. Then talk to her and she will give you the soothe bell.
Go to the Pokemon cente in eterna and talk to the lady with brown hair and she will give you the happiness app (the one with all your Pokemon floating around and bumping into each other). Hold your stylus on apokemon of your choice and if 2 big hearts come out of it, its happiness is near if not full.
Make your Pokemon have happiness if talked to.
In salport city there is a woman looking at a picture in the Pokemon fanclub. Make sure the first Pokemon in your party has full happiness's. Then talk to her and she will give you the soothe bell.
Train them by battling but make sure they don't get to faint, everytime you need to revive your Pokemon they're happiness points go down. ofc Pokemon's happiness comes back but it always slows the process of getting maximum happiness to your Pokemon. Just by walking around with your Pokemon gives them happiness. Other things is to give your Pokemon a SootheBell to hold, it gains extra happiness in every battle you've won. You can also get them a haircut in GoldenRod Underground to get some more happiness. This makes Pokemon really friendly.