Done well, the task in hand is a process of discovery. There is a space for planning, and ideas, and thoughts, and random words, phrases, paragraphs scribbled down on scraps of paper. There are times for drawing up plans, diagrams, lists. Notes on characters, maybe, and the exact sequence of some plot development.
But you can't really do any of that - not do it to any purpose - if what you have at the heart of your project, is a blank space. Notes upon notes. People you can talk about, even describe in detail, but not show. Reams of words, none of which tell a story.
How does Katie (scroll down, 'homework' box) spend the day, after that early shock? All the technicalities, all the how-she-gets-from-there-to-here, the thoughts around what - and who - needs space, what/who needs to be travelled through in a sentence, can be planned, and usefully. But write the words first. Open up to the possibilities.
As above, so below. Simple phrase, too many links to choose one, and if you Google it, you'll find lots of analysis and history. But the phrase, not the analysis, delivers the meaning.