Remember that the north star will always be to the north, and it will
not change its position at all. The fake north star is usually to the
northeast, and it can change position. The evening star is to the west,
it moves west as you walk north, and it sinks lower and lower in the
sky as you walk east. Also take note that it's four turns (or four
d-pad taps) to change a cardinal direction.
Now, here are the traditional directions to the Oasis. First, follow
the north star for two nights so that the evening star hangs in the sky
directly to the west. Then head east until the evening star sinks below
the horizon and you can no longer see it (it should be about two and a
half nights). Once the evening star disappears, head north again for
about three nights, and you should reach the Oasis.
But if you really want to cake-walk through the desert, here's the
ULTIMATE SHORTCUT. From the start, turn so that you're facing between
the true and fake north stars (it should be 1 turn right from facing
north). Now just walk in that direction until you reach the Oasis. Too
easy, right?
Be sure to follow these directions and not the directions that Horis
writes down for you, because they are wrong. When you're ready,
examine the big vase near the save book and fill your canteen with
water (you'll get 16 helpings). Then rest up, save your game, and head
out into the desert.
EXTRA NOTE: There are a few good items that can be found in the desert,
the most noteworthy being the Life Armor and Royal Sword. Going after
these items is entirely optional, and some of them can even be obtained
through other means. Normally, getting these items requires taking
multiple trips through the desert, but there is actually a way to get
from the Factory to the Oasis while picking up both the Life Armor and
Royal Sword along the way! If you're interested in getting any of these
optional items, check the Long Trips in the Desert section under Side
Quests