Over the years I've heard of tanning hides with different things but was never interested in using harsh chemicals that we would have to order and that might be toxic. We met a man several years back that mentioned that he did brain tanning. That really piqued our interest. Brain tanned deer hide makes a nice soft leather that is good for clothing. I'll give you the basic instructions that we used and then you will learn to tweak the process as you gain experience.
Peel the deer hide off the carcass being careful not to cut the hide. There will be a little meat on it. Work as fast as you safely can so the hide doesn't dry out. It also helps to work in the shade, if possible.
Starting at the neck, begin scraping the flesh off of the hide using a dull draw knife. You will see "vein tracks" and you want to scrape them off, also. You will see pinholes in the hide when you are done.
Turn the hide over and, starting at the neck, use the drawknife to scrape off the hair. Keep scraping until you have the skin off the hide.You will see vein tracks again. (You can soak the hide in water at any time to keep it until you can get to it. Change the water ever so often. Adding lime to the water will help loosen the hair.)
Tie the hide on a frame using slip knots so you can easily adjust it.
Scrape from top to bottom with the edge of an axe blade to remove moisture and stretch.When it starts to dry it will fluff up. You will need to tighten it as it dries but don't overtighten. Let the hide dry a few hours or overnight.
Start a fire that will smoke. You want smoke not flame. Tent the hide over the fire leaving a chimney at the top for the smoke to escape. Let it smoke this way for 15 minutes and then do the other side. Be checking for flareups in your fire and make sure it isn't too hot inside the tent. You don't want to cook it.
Put the brain that you have removed from the skull of the deer in warm water and squish it up. Push the hide down in the solution and work it. Check after about 15 minutes to see if it has taken up enough moisture and it will stretch. Wring the moisture out over the container so that you don't lose it because you can use the same solution for up to 8 hides. Scrape again with the drawknife being careful not to make holes. Put back in the solution, swish it around, and leave it for a while. Take it out and wring it out thoroughly. Pull it apart to stretch the fibers and keep stretching until it seems right. (You can set it aside for a little while and keep coming back to stretch it.)
Now that you know that it isn't too difficult, I hope this will help you get started. Sorry there aren't more pictures but the weather was lousy at the time.
Genesis 3:21 "Unto Adam also and to his wife did the Lord God make coats of skins, and clothed them."