Use the "Duplicate items" glitch on a potion of strong health (to get 90 potions). Repeat the duplication to get the desired amount of potions. Open your inventory and go to the strong potion of health. Press Triangle to quick link it to one of the Analog-stick directions. When you are low on health, just tap the quick link direction to use a potion. When running low on health potions, repeat the duplication process.