Just diving in doesn’t work. How do I know? Because it’s my default approach to writing, and I have boxes (and hard drives) full of unfinished stories. But allow me to clarify: By “diving in” I mean writing before your premise has fully percolated. When I have a strong premise, the work is virtually automatic — it’s not a rote process at all. In fact, it’s quite exciting because my confidence carries me through the task. Having that premise firmly locked in along with some character and plot detail is the surest cure for writer’s block. Anyone claiming to suffer from such a block probably doesn’t have a firm grasp on what he’s trying to say, and thus misunderstands his own cognitive hiccups.
I’ve heard it said that writing off the cuff is a great tool for loosening one’s compositional muscles. I’ll accept that notion and will even concede that it’ll yield ideas for later development. But as a method for true work, the approach is faulty. Let my multitude of half-finished tales be your proof.
How then do you know when an idea is ready? Are you married? Have you ever been in love? Then you know finding a mate isn’t a mathematical process. No one ticks off the cells of a spreadsheet when bonding with their significant other. When you’re in love, you know it and you proceed with clarity and focus.
So, are you in love with your premise? If not, attacking it right now would be a bad idea. Wait until two or more ideas have conjoined around at least a basic narrative spine. Wait until you can’t wait anymore; until you’re burning to get the thing down. If you never work up a true eagerness to share that story with the world then you’ve chosen the wrong story. If you’re not eager to write it, why should I be eager to read it?
Remember: Just diving in doesn’t work.