I started the never-ending pursuit of lithic studies as a child. I spent 24 years in the USAF and never stopped that pursuit.
I have demonstrated knapping for archaeological societies, schools, and Universities (I am familiar and competent in techniques of all periods from most every continent, as well as other technologies...but there is always more to learn!! I also am a weapons maker concentrating on the Migration/Viking periods of Scandinvia and Baltic area. I have done living history in Norway (both prehistoric and Viking period. I am now spending most summers in Scandinavia and Europe). I have countless hours in both excavation and in the lab in identifying lithics and Native American artifacts.
I guess the best advice I can give, especially in the pursuit of lithic studies is learn from what you do...knapping itself is not too difficult in theory but your failures teach you as much if not more than your successes. Remember you must replicate the failures seen in your production model that is found in the record. They were not perfect then either. Additionally, each stone artifact has a "recipe" in its creation. Many copy things morphological correct but miss the details that truly replicate. One must immerse themselves by studying the actual artefacts, both complete and broken in their many states, to try and fully grasp this recipe. I love the process of experimental archaeology and wish it existed more here in the United States.