First, obtain a bar of round steel or iron stock about 1/4" in diameter. Light your forge and let it settle down, then start heating the rod about 3/4" along.
Turn on the blast, and get the iron to red heat. Upset the rod to about 3/8" thick.
Reheat, this time heating the end of the rod. Hammer the end of the bar to a flattened spread arc. Next we curl the arc around into a circular cross-section, using another bar or an anvil horn, then hammering it closed. This forms the end of the arrow head that is mated with the wooden shaft.
The next step is to heat the rod just a little beyond the upset, and hot cut it. Using tongs, reheat this cut end, and hammer to a square section. Do not taper or draw the point, as a long thin point will tend to bend when it hits an armoured target, and will also tend to slow the impact down more before penetration is complete.
When happy with the squareness and straightness of the head, quench rapidly in water to harden the cutting edges and the nose, but do not quench further back than just behind the upset, as this may cause the arrow to shatter at the thinner neck on impact, rather than give slightly.
The arrowhead is then matched to a fletched shaft, and stored ready for use.