Gather your materials together and start using the sharp rock you got to smoothen the block of wood as much as you can. Make it shaped like a box. Make it as thin as you can so it's easier later. Then make a "v" shaped notch to put the stick on. After that, place grass on the bark close to you and then put the block of wood over the grass on top. Grab your stick and hold it tight on the edge of the wood and start spinning it as fast as you can. Charcoal dust should start falling out of the wood with a little smoke in it. This is happening because of the friction of the stick you're spinning with the wood bard. It should fall onto the grass. Once there is a good amount of charcoal / ember on it, start to gently blow on it. As you blow on it, a lot of smoke should start to form. And you've got yourself a fire! You can hold the bark and flip it over into your campfire you're going to use to cook food or to make yourself warm. You can put twigs and sticks to keep it going. Not too much though!
https://en.wikipedia.org/wiki/Campfire
From Wikimedia Commons, the free media repository cc by:SA 3.0
http://foodfacts.mercola.com/coconut.html
by Dr.Mecola
cc by: anna1311
First of all, you have to have a coconut. Try to get a bigger one for more tinder. Now you have to get through the husk to get the hairy stuff inside which is the tinder. You might think that we have to use tools and stuff, but gravity is stronger! First, surround your coconut with rocks to secure it. Then try to find the heaviest rock you can lift. Drop it onto the coconut a few times. It should start form lines because it's weakening the structure of the husk. That's a very good sign. Once the lines are more opened up you should give it one more smack on the other side of the coconut with the rock. Now dig your fingers in the lines and open it up. You'll see a bunch of hairy and fibery stuff in their which is the tinder. Just rip it off and you could use that for your fire replacing the grass.
Information from https://www.youtube.com/watch?v=T9bXoOa1qTg
King of Random(Grant Thompson)