Lost is not knowing where you are, or which way you should go. Stranded is [usually] knowing where you are but no one else seems to know where you are. Now according to most survival books, websites and search & rescue (SAR) teams. RULE # 1 - Before you take off and go anywhere you should tell someone (a) where you are going and (b) what time you will be back or be arriving at your final destination. Just in case you don't make it back or to your final destination within a certain time a search and rescue (SAR) party will know where to start looking for you. RULE #2 - Should you become lost or stranded in a disabled vehicle or you're a survivor of a plane crash, it's best to remain with the vehicle or plane. As it will be easier for a SAR party to find you in a stationery position than to look for a moving person or a group of people who have no idea where they are going. If there's no vehicle or plane and you are on foot and you have no idea where in the hell you are or which way you should go. Then again, it's best to stay where you are as it will be easier for a SAR party to find you in a stationery position then to try to look for you wandering around aimlessly not knowing where you are going. If you broke RULE # 1 - Failed to tell someone where you are going before you took off.. Then you can skip RULE # 2 and proceed directly to RULE # 3 - DON'T PANIC & LOSE YOUR HEAD, S.T.O.P..
Stop moving, sit down, relax, and think where you may have got lost. Observe your surroundings and try back tracking a little bit. See if you can recognize the terrain. And if you don't, sit down, take a deep breath and admit to yourself...
"Well it looks like I'm lost, what should I plan to do next?"
Well for starters you should listen up for signs of civilization. Such as listening for sounds of vehicles, trains, church bells, factory noise, etc.. This will give you a general sense of direction as to which way civilization might be located. If you do not hear anything, then look around and proceed to the nearest and highest piece of ground. From there look for buildings, towns, church steeples, roads, railroad tracks, fences, power lines, telephone lines, etc.. This will lead you back to civilization.
If there's no high ground then climb the nearest and tallest tree. If you do not see or hear any signs of civilization but you see a stream, creek or river, then follow that instead.
Bodies of water will not only provide you a source of water for drinking but will most likely lead you back to civilization. Possibly to some trails or roads that will get you back to civilization.
Should you be on the move and you don't see or hear anything that can help guide you back to civilization, weather changes, temperature changes, darkness is quickly approaching.
It's best to stop and stay where you are for the night. Begin building a shelter and fire before it's too late. Leave yourself plenty of daylight to build the shelter and fire, several hours.
Avoid the risks of getting wet, cold and not seeing where you're going.