[Zeke]

Jump up, stab down. Doesn't sound like much, but it's one of the most powerful moves in any Zelda game. AoL is very hard before you get Down Thrust; after that the difficulty is more normal, though it picks up again at the final palace. The move is also found in Minish Cap, though it's less useful there.

I agree that Heart Pieces are mostly for completists. Unlike Energy Tanks in Metroid or Sub-Tanks in Mega Man, you don't need to hunt for them to increase your capacity, since every boss coughs up a full Heart Container. However, it must be said... anyone can be an expert at Wind Waker. Parry Attacks make it easy to take down even the strongest opponents. (There's also a new bottle item, Link's grandmother's soup, which costs nothing, holds two doses, refills your health fully, and doubles your attack power till you get hit. At least you can only carry one of them....)