Make a shelter. You want it to be out on the beach near the ocean so that you have a good view of any ships or anything else that might pass by you and your island. You are the only lookout so make sure you can see everything.

Make sure the area is clean and open, but be near some trees. Trees will be your shade for what is most likely a hot, beating sun. Find some trees to help you set up against and make sure to use their leaves and branches as shade.

Make a bed that is up and off of the ground. You do not know what will be crawling around at night and you don't want those things in your bed. One way to do this is to make an "A" shelter. Set up two sets of two large branches about 7 or 8 feet apart (this is the length of your bed). Stick them in the ground (or leaning against a tree) so that the they cross in the middle, high enough that you can lay under it. Put some branches going across on either side of the "A"s. This is your bed, and if you can find something to tie it, you'll be able to place it a few feet off of the ground. Try to make it comfortable and give it a roof. Use what you can--leaves or giant plants.