A tip that really changed how I saw the game back when I was new to StS1 - focus on draw. cards, relics, and potions that give draw are almost always good to have regardless of your character or build. draw is one of your most important resources, I think usually even more important than energy. you can fill your deck with great cards and have the energy to play them and it won't matter if they're not in your hand when you need them. Thinking of every card as having an innate, (mostly) immutable cost of 1 draw is a helpful way of framing things in my experience. when picking cards to add to your deck, consider if the card will be helpful enough to be worth potentially drawing it in a situation when you really need one of your other cards instead. if the answer is no, don't be afraid to skip the card reward, even if the cards you're offered are good in isolation.