Maiamais and equipment improvements
Visit Mother Maiamai to begin the search. Listen for the cries, use wall merging to dislodge wall-bound Maiamais and revisit rocks and deep water with upgraded equipment.
Buy an item from Ravio before asking Mother Maiamai to improve it. Rentals cannot receive those permanent upgrades.
Collect the four Master Ore pieces and take the pairs to the appropriate blacksmiths. Search the bottle locations separately; an empty bottle is a permanent reward even if its contents change.