Finding yourself on a deserted island, one of the rarest experiences one could expect to encounter, is almost always an accident. Usually people find themselves stranded due to a tragic event such as a plane crash or a ship wreck. It's important in this situation to put the tragedy on the back burner and to focus on survival. Keep your wits about you, and always be aware of your surroundings. On an island, you may be hunted by animals or injured from making silly mistakes. Injury and illness are both hard to overcome in the wilderness so keep yourself as safe as possible. Scavenge anything and everything you can, concentrating hardest on objects that aid you in collecting water and implements that can be used as tools.
Sift through the wreckage. Look for items from your wreck or crash that can be of assistance to you. Take any metal scraps that could be repurposed as tools. Look for lighters or matches that could be used to start a fire. Pick up cooking utensils or necessities such as soap or a toothbrush. Grab any hardware, knives, first aid kits, food and clothing that you are able to locate. Visualise seemingly pointless materials as something else. For example, you might use a tablecloth as a blanket or as a shade tent. In this situation you must be resourceful and open to using objects for multiple purposes.
Make a shelter. Use debris from your wreck, or collect fallen limbs from trees. Shelter is important, as the sun can be one of your worst enemies on an island. It's important to avoid sunburn as much as possible. Set up your shelter on the beach so that it is visible to boats or planes that may pass near the island. Create an additional shelter under tree cover so that you can rest there during the sunniest days or hours.
Look for a running water source or make water traps. Create a watershed area that drains rainfall runoff into a low point and find a way to trap water at the low point. Never drink water from the ocean as it will dehydrate you. Rainwater is your best bet at hydration on an island. Look to the foliage and squeeze any available water from the foliage for consumption.
Plan to catch food. You should avoid most plants on the island unless you are familiar with plant types. Many plants are poisonous to humans. Focus on catching fish. You create a spear by whittling a stick so that it has a sharp point. Use a knife or a jagged stone to whittle the stick.
Make your own sunscreen. Sunburns can cause dehydration and, if the burns are severe enough, they can cause infection. Use the milk from coconuts to spread on your exposed body parts. Use sand or mud to cover yourself as well. Mud will help shield your body from the sun and will also act as a cooling agent to offer you some relief from the heat.