Among all the rubbish on youtube there are some videos that can teach you alot. Some time ago I was walking the country side and I found a path made of small stones, rocks and gravel. some of the stones were shining in the sun like glass and I realised that those stones might be flint and I always wanted to try some flintknapping. dispite the fact that the stones were rather small I decided to give it a try and I brought kilo's home with me. I tried flintknapping and it didn't work. So I tried to find flintknapping tutorials on youtube to see what I did wrong. Lot of usefull stuff but then I found a video about practicing with glass. so I tried it and I got myself a nice arrowhead.
After trying glassknapping for a while I realised 3 things
1- Glass is not as durable as flint, it breaks more easily
2- Glass is easier to work with then flint
3- Glass is easier to find in nature (bottles, rubbish) then flint.. I know it shouldn't be.
Also some things are better to make out of flint then out of glass. A (hand) axe for example. The more I practice the better I get at it and it is a fun skill to learn aswell