Once you have an Onmoraki (Onion Chicken persona) that is found earlier in the game, level it up to Level 15 to learn Confusion Boost and Pulinpa. Then, fuse Onmoraki with any desired persona. Since you can always farm on the Easy difficulty, it is recommended you select a persona with higher Luck to maximize your gains. If not, select whatever you are comfortable with and make sure to inherit Confusion Boost and Pulinpa. Next, level up the persona through Gallows Fusion, using the highest level Gem persona you are able to summon as Fodder. Following each Gallows Fusion, you must register the persona, delete it (Itemization or Fodder), and re-summon it again since the game does not allow strengthening a single persona more than once. After doing this, gather about three Memento Requests since not all Memento bosses can be confused. Make sure the difficulty is set to Easy, you have an SP regenerating accessory equipped, and only have the protagonist in your party (turns go faster this way). Finally, find and confuse the Memento boss, then keep guarding it until you have to confuse it again. Depending on your "Luck", the Boss should be throwing money, items, or even nothing at you. If you are doing everything correctly, you should not be taking much damage and can farming while doing other things. Simply press Triangle then X to confuse and Circle then X to guard. This method allows you to earn between 40,000 to 170,000 per enemy turn.