A number of Pokémon in Shining Diamond and Shining Pearl require high friendship to evolve. The list includes high-level Pokémon like Budew, Chingling, and Eeevee if you want Umbreon or Sylveon. Friendship hacks for Pokémon Brilliant Diamond and Brilliant Pearl are therefore much discussed, but there is a simple method that is becoming little discussed: take a walk with your Pokémon.
In my gaming experience, I have found that once I walk around an hour with one of my Pokémon and then check our friendship levels in the Pokétch, I will see a heart where it wasn't there before. In other words, having my Pokémon walk with me made a huge difference. It seems that talking about my Chingling for a walk was also the instigator to evolve into Chimecho.
Of course, walking alone won't solve the friendship puzzle. But it works beautifully in tandem with other methods like keeping Pokémon in your party, feeding them the types of Poffin they prefer, giving them massages to Pietravela, and giving them vitamins.
To unlock the ability to walk with a Pokémon, you will need to have gone for a walk in Friendship Square in Hearthome City. Afterwards, any Pokémon on your team can walk alongside you, wherever you go. From the Pokémon menu, simply choose “walk together” and your Pokémon will follow you on your adventures.
