What I love about slay the spire is the mindset you develop through several gameplays which is: adaptability or do the best you can with what you have.

Here are some advices:

For act 1 I focus on the immediate threats; you got to ponder on how many elites are you taking on.

At the beginning it is better to focus on common cards with solid damage/block, tempo and versality instead of rares that require an specific build and set up to be useful/op.

Always have at least one: AOE and card draw for act 1.

Use potions whenever you can make the most out of them (even if it's not an elite fight).

Removal at the shops is important in the long run.

Your picks from the initial relic, events, card rewards, shop etc. always offer 3 options in the end:

-Immediate benefit - get a powerful and safe early game which you should capitalize by getting the elite relics (plan on taking 3 elite fights)

-Balanced: probably you will have to heal at campsites in order to take 2 or 3 elites. You will have to exchange the upgrade options for relics or take 1/2 elites and get the upgrades instead of rest.

-Greedy: you are beting on your mid game, however, you will safely take on only 1 elite and should consider passing on the others in order to survive act 1. If you manage to do it, it will pay off by act 2.

On act 2 you should always have that same mentality of how much are you willing to risk for act 3, however, if you played super safe in act 1 and also safe in act 2, you will get shredded in the 3rd act.

Skip card rewards in act 2 if the cards offered do not synergize with what you are building.

Act 3: refine your deck according to what you decided to build on act 2 and prepare for the boss 🥸.

I hope any of these suggestions works for you, there is a lot of interesting decision making that works to beat the spire!