How do I refill my PP?

Solution 1:

There are several options for restoring your PP in Earthbound.

1. Sleeping will always restore you PP. This is typically done at hotels.
2. Touching a magic butterfly will restore 20pp to every character. These are not limited but rather have a chance to spawn at certain locations when visiting areas.
3. Consuming certain items such as PSI caramels (limited in supply) or Brain Food Lunches (sold towards the end of the game). The fourth character can recover PP by drinking water.
4. Lucky Sandwiches, if you're willing to deal with some randomness, or exploit the RNG. Details here.
5. Paula and the fourth character can learn the PSI Magnet line of abilities, which allow them to semi-reliably drain PP from enemies.