Do you have any personal DMing or writing tips, you wish you knew when you were younger?

Sure. Let your players tell THEIR story, don't inflict prepared stories on them.
Every life is a series of moral choices; give PCs chances to make theirs.
What do your players like most, when gaming? Give those things to them, and let them spread their wings.

— Ed Greenwood (@TheEdVerse) January 23, 2021