I have watched many youtube videos on making primitive flint broadheads. The video below is a good start. 

The hard part is finding good flint or some say chert to knap. I bought some Texas Chert on eBay. 

It was extremely hard to knap.

However, I made dozens of mistakes and a pile of rubble, thus I am learning. Was I successful in creating my first flint head? No, but I learned a lot. Some flint bearing rocks are easier to knap than others.  There are many types of stone chert. I am undaunted, in my desire to create my first flint broadhead. I think that with the right material, I will find success. What will I do with it? Time will tell. The sharpest chert is perhaps obsidian, its like glass. As a bow hunter it is essential to have sharp broadheads.  Care should be taken to wear gloves to prevent cuts when knapping.

I’ll let you know if I am successful in my quest. 

Good Luck Knapping