The most important thing to do when you are lost when camping or hiking is to not panic. Do not make any sudden decisions without thoroughly thinking through your situation. Once you realize you are lost, take time to assess your predicament. Examine all the possibilities. You have more time than you imagine. Extra time spent analyzing all the options will prove valuable in the long run.
Now that you are calm, figure out how you came to be lost. Did you misread the map? Did you leave the marked trail? Do you believe you are wandering in circles? How and when did you go off course? Is it possible to backtrack, or retrace your steps, to reach familiar territory? If you can figure how you got lost then maybe you can correct your errors. If not, then you need to decide how to proceed.
If you know the direction you need to go, try to remember where the sun came up or set. That will give you east and west bearings. In fact, you should make a special note of the sun rising the first morning you are in the woods and then file that information away in case you become lost.When you start moving you have two purposes in mind. The first is to find your way to safety. The second is to put yourself in a position where someone can find you. If someone knows you are camping or hiking and will start looking for you when you do not show up, then you need to figure out where they will start searching for you. Did you let them know where you would be? If so, try to make it as easy as possible to find you. Mark your trail as you walk. Use strips of colorful clothing. Leave notes. Break off branches. Your purpose is to alert a search party so they can follow your path of travel. Look at each sign you leave with an eye towards how someone would view it.
Remember to conserve your energy and water. You need to drink enough water to stay hydrated. If you can find a source of clean drinking water store as much as possible a if you are prepared with a small water filter that is ideal. You will need that water. Stay on course. Do not second guess yourself once you have a plan. Keep moving and soon you will either find your way out of the woods or someone else will find you. Be confident.