I've talked with alot of knappers/hunters on this subject,Most all agree,about edges,w/l ratios,and such. One thing they are all adamant about though is the base. Get it thin tapering to the thickest area of the point(center ridge) just where the arrow tapers out onto the point. The Clovis people are a prime example of this,fluting points in such a way to have the least resistance (shaft to point) to aid in penetration.
Works the same with arrow points,imo.
Another thing that some point out is a thing called "buroen" Not sure how to spell it, but basically it's making a diamond or "Z" shape on the tip. You only get one chance to get it right (of you shorten your point)
. It envolves taking one flake from each corner of the tip to reveal a sharp clean edge.
Not easy to accomplish,but man it makes a scary sharp "chisel"tip.