How do you draw? What's your secret? Help!!

I'm desperate as this is a skill I been trying to have for so long (literally my whole life trying to be skillful, or just ok). I had seen YouTube tutorials, read books, I practice a lot but my strokes just feel wrong. I want to know how you do it, please. Do you always copy something? Do you measure it? And then how do you lines that work? Do you erase a lot? How is your hand posture? Even in real time tutorials I don't grasp how the magic is done