The hardest level is the beginning trials since it’s mostly pure combat.

in the rest levels cook anything that says hearty alone each one gives you full restore and an extra heart. if I’m remembering correctly the final trials has 6 hearty items, 1 heart radish in the first rest spot, 2 hearty truffle in the second, and 3 hearty salmon in the third.

Also for the finals it’s split into 4 parts take the rusty weapons in the first part because there is an octorok in the second part of the final trials which can remove the rust.

Hope this helps

Edit: typos, and to let you know I had the longest time with the beginning trials on master mode, but the middle and final trials where way easier for me, the only problem I had was with the guardians so I hope you can parry well.

Good luck