For me it was advice from Dan Harmon: “Don’t try to prove you’re a good writer, you’ll never write anything. Try to prove you’re a bad writer and you’ll write everything.” Not perfect advice but it really does help me write when I’m being overly critical of my ideas.
For me it was something along the lines of “you can’t edit a blank page”. And I know, it’s a meme, but “just write, edit later”. I used to get lost in planning and world building and then I discovered that I’m more of a pantser than a planner and voilá, here I am, actually finishing stuff.
Also, I came to like editing and revising now. I used to dislike it but now I enjoy it!