Really good flintknappers are highly skilled, and typically have spent years perfecting their craft. Modern flint workers can replicate any of the older, highly intricate points perfected in the past. If you know what you are doing, making a point usually takes very little time - perhaps five minutes or so.

Then there are the rest of us. We can get by at a much more basic level. Take rock, hit it with something hard. Sort through the pieces and find one with a suitable edge. Use it (it will dull rapidly). Discard and hit rock again. Repeat as needed.

A lot of cutting was done with random scraps of flint, obsidian, or whatever was around that are virtually indistinguishable from natural bits. They are quite effective. One of my professors carved up an unexpectedly deceased circus elephant with such "tools" and the job went quite well.

The trick is having suitable rock. Good chipping material is quite rare, highly valued, and was often traded over long distances prehistorically - obsidian from Yellowstone has shown up in Illinois and Ohio. You may have to work with less desirable material. It happens that some of the best material to knapp is glass - it is more uniform and predictable than most natural stuff.

There is a reason why metal knives were a popular trade item to group depending upon stone cutting tools. Metal is stronger, more durable, and holds an edge longer than stone.

Frankly, I would not put a lot of emphasis on flintknapping as a survival skill. The easiest way today to obtain a flint knife or arrow head is to find one discarded or lost in the past. It is even easier to carry the cutting instrument of your choice.