Instructions
Familiarize yourself with Hyrule Field and the locations of the different temples and towns. Traveling across the whole map takes time (even when you have a horse to ride), so it's best to know where you're going before setting off for the next challenge.
Avoid making bosses and puzzles out to be more difficult than they are. The puzzles in the game rarely have complicated solutions, so you'll have an easier time beating the dungeons if you're not afraid to try the simple solution first.
Take your time to explore Hyrule in search of goodies. The plot is fairly linear, so you can still beat the game by going straight from dungeon to dungeon, but you'll have an easier time doing it with the extra tools you can unearth along the way.
Remember that once you acquire the Ocarina of Time, you can travel back and forth between your quest as a child and as an adult. If you forget to do something, don't worry, because you can always go back and finish it up.
Make sure you're well stocked before heading into a boss fight. A full collection of arrows, bombs, hearts and fairies is essential to succeed against the more difficult bosses.
Keep an eye out for signs on the ground or walls that direct you to play your ocarina. These spots often function as keys and will open doors to temples and new areas if you play the right tune.
Look for spots to plant magic beans when you're playing as young Link. Beans planted in these places will grow to become magical plants when you're an adult and will help you get to hard-to-reach places.