Final Preparations
After the story sequence you're back at the Desert Colossus. Use the
Prelude of Light to go to the Temple of Time. Another, very informative
story sequence follows in which you get the Light Arrows. Now, go around
Hyrule and finish up all your unfinished business. Get all the remaining
heart container pieces, complete the trading sequences, kill gold
skulltulas you've missed, catch all the 10 Big Poes, catch a huge fish.
If you want you can do the very first part of Gannon's Castle to quickly
get the Golden Gauntlets and the double defense, which can help you get
other things, and then leave the castle and come back after you get
everything else. Get everything you can out of this awesome game,
because the next step is the final level, Gannon's Castle. When you're
ready, make sure you have at least 1 blue potion found in the weird
potion shop behind the regular potion shop in Kakariko Village) and some
fairies and head to Gannon's Castle. Walk up the steps and a bridge will
be formed for you. Head into the castle.