You have numerous books on screenwriting and also as many screenwriting gurus. Everybody has a recipe how to write next big thing. But we have to really question ourselves. Can screenwriting be taught? There are many discussions and many books written, but still not everybody makes it. Just few of them. So what is then the point?
I think that you can learn screenwriting till some degree, but then you are on your own and only your talent and your hard work counts! So, best learning of screenwriting is by doing it! Not reading, not going to curses, but by writing it! Quantity produces Quality! That’s the only rule. And of course – you also need guts and luck. 🙂