Raise Togepi’s friendship/high happiness to a high level
Level up Togepi once its friendship is high enough
In some games, use a Soothe Bell, walk with Togepi, and avoid letting it faint to build friendship faster
In Pokémon Legends: Arceus, use a Friendship evolution method and level up when friendship is high
Togepi evolves into Togetic when it levels up with high friendship