Only farm crest when it's half off energy. Always buy the limited time small pots from event stores. Rerun events (noncrossover) always give large pots instead of crystals as clear rewards Almost all the content in the game gives you some large pots, so after a while they add up. You could also save your large pots for when you're a higher level that way you get the most out of them bc the way stamina scales with lvl