Charcoal has many uses, whether you want it for your grill or to use in art, it even has anti-odor and anti-moisture properties. Actually there are a lot more uses for charcoal than most think but for me, I just want to burn it. It's better than plain timber and allows me easier control of my forge fire.
To make charcoal you basically have to bake the wood in an oven. Burning the wood with minimal oxygen allows for a process known as pyrolysis.

What you'll need

Small pieces of wood.
A sealable metal container, eg a paint tin
Fireeeeeee

All in all this took me about 3 hours but its also a kind of set and forget thing. Obviously when you're dealing with fire you need to be vigilant but making charcoal isn't something that requires you to be there the entire time.

Step 1

Take your empty paint tin and fill it with small pieces of timber. Hardwood is best but i used a mixture of whatever was laying around the property that would fit without me needing to cut it.

Take a nail or a file or basically anything sharp and pierce a hole in the center of the lid of your tin, this will allow the gases created in the heating to escape and release pressure inside your canister. It also gives us a way to figure out when our charcoal is done which ill explain later.

Step 2

Fire.
Okay maybe this should be step one since i actually lit my fire first before i did anything else but basically all you do now is put your tin into the fire. Depending on the size of your pieces, what timber they actually are and how much moisture they hold the process can take varying times. For me this took approx 2 and a half hours including prep.

Once you throw your tin in the fire and it heats up for a while you'll notice a steam coming from the hole you put in your tin, this means the pyrolosis is starting to take effect and the moisture and other contaminants in the timber are being cooked out (essentially.

After a while if you hold a flame to this steam it will catch alight and stay lit creating a mini flamethrower out the top of your tin :D It took about 45 minutes for my tin to get to this point, Because I was set up in a fairly safe area I was able to set it in the fire and go do other things nearby but when dealing with fire, especially if you live rural always be wary of the dangers.

How to know when it's done.

Basically once the wood has been heated to over 400 degrees and the moisture has been removed you have yourself charcoal. Once you heat it past this point you are making higher quality charcoal but for most home uses its probably not necessary.
An easy way to tell when your char is ready is when the flame that is coming out of the top of your tin goes out and will not relight. Once this happens you can take your can out of the heat and let it cool down. Once you open it up you should have a nice tin of charcoal.

This is a very basic and simple method and can easily be scaled down or up to suit your needs. You'll probably get between 25%-50% of the volume of timber in charcoal. Commercial production can achieve as high as 90% but good luck with that.
An easy way to scale down, use a coffee tin.
An easy way to scale up, use a 44 gallon drum.

The process remains the same but the time to complete will vary. Test out different timbers and see what results you get. Dry hardwood is optimum but definitely not necessary.