I will trim away the extra wood after I tie the head on.
To tie the head to the shaft, I use the sinew I save from the loins/backstraps from my deer.
It separates into nice thin threads.
I soaked the sinew threads in cold water to soften and stretch them. While waiting, I stained the wood shaft. The sinew does not really get tied onto the shaft. It is more like wrapping a wet noodle around the shaft. After I put on a few layers, I dried it with a blow dryer (just like I'm sure the early people did). This makes it shrink tight. I then rub the sinew with a block of bees wax to waterproof it so it won't get wet and loosen up.