Pandabean.
When I made my first bow drill, it took me three days to get it to light anything. I had all the dry grass you could wish for, but had not been shown the difference between the dark brown embers, and the near black ones, so did not know why they would not light the char cloth, tissue or grass I had lol.
I remember being so tired, that when it became time to speed up to get the embers really going well, I was looking down at my bowing arm and it was simply refusing to do what my brain was telling it! I was thinking 'come on now faster faster' while watching it get slower and slower lol.
The odd, but very important thing was that once I could do it, it became very easy, and I now can get good embers almost instantly.
Practicing anything, and practicing it in real life environments is always time well spent.