Make sure you have the Red Mail before trying to do this. At least 14 Heart Containers helps as well... and a Red Potion. Most of the areas shouldn't be too difficult with the Red Mail, except for two... the one with the Mirror Wizzrobes/Super Darknuts, and the block puzzle one. Keep trying!
If there is one area you absolutely cannot beat, you could always just buy a key for 500 rupees on Volcano Island.