In our quest to get cheap homemade larp armor, we started a chainmail coif and already made the top piece.
Next come parts 2&3 - the headband and the main body. These can be made together actually.First thing to do would be to take measurements. Put on a thick winter hat and then measure the size of your head from one temple to the other. This will be roughly the size of the main body. The winter hat represents padding, which you will need anyway. All in all don't be afraid to make it 2-3-4sm bigger, the extra room is necessary, its best if its a loose fit, rather than not fitting at all. Then measure the full size of your head with forehead included - thats the size of the headband.
Here is a top piece with the headband already attached. The headband is simply a band of 4in1 chainmail with the length you measured from your head earlier. Now is the time for adjustments. If the top piece is too small you should add an extra roll to it, and if the headband is too tight - make it bigger.
Next thing to do is to make the main bodies of the coif. The size should be according to the first measurement we took for width and long enough to cover all of your neck. As you can see I am making two coifs at the same time. For the second one, headband and main body are being done together. It makes no difference really.
Then you must attach the top to the main body. I find it is easiest to do it over your knee.
Once that's done, the coif is finally taking shape. Now we need to close the lower part of the main body with a small rectangular piece of 4in1.
Finally our larp armor project has reached wearable state. When closing the main body - again make sure you can fit your head with padding on. Then you can go on to adjust the size of the face to your liking.
The last thing to do would be the mantle. There are many variants, you can even go on without one and attach the coif to an existing hauberk. I will do a simple bishop mantle for this later on.