Bottle/Tin can/birch bark cone etc.
Coarse Gravel
Gravel
Coarse Sand
Fine Sand
Cloth
What your going to do is get your self a bottle or tin can and for a tin can your going to poke 5-10 holes in the bottom of the can. For the bottle your going to cut the bottom off the bottle so that you still have the drinking spout. Next your going to get some cloth and your going to either lay it over the holes or stuff it into the neck of the bottle.
To be honest if your out in the wild and you don’t have access to these different types of materials as long as you have access to some sand, and gravel it should be fine. Start out by placing the fine sand at the bottom of the container on top of the cloth. Then put the coarse sand, fine gravel and finally the coarse gravel.
Once this has been made simply pour the water into the container and wait for the water to filter through. Do this several times to make sure everything has been taken out. If you do have access to activated charcoal (helps take out bacteria) then you would place this above the sand.
There you have it your very own survival water filter. Now keep in mind that after you filter it, it is still a good idea that you boil the water to ensure that the water is of the quality needed.