Here are some hints (in no particular order) that I’ve found useful for overcoming those stumbling blocks when the words don’t want to come, or the story doesn’t want to work:
What is the block telling you about your story? Do you not know the characters and their motivations well enough? Is the world building letting you down? What does the character want; what’s stopping them from achieving it?
A shower or a walk can be useful ways to give the mind a rest and let the back brain work on the problem.
Try printing out the yarn, maybe in a different font to usual, and take it somewhere you don’t often work. The fresh appearance and/or the fresh environment might help you see the story from a different angle.
Talk it out. Having to describe your story, your character, the dilemma, to someone else can help you twig. Logic-testing your story to another inquiring mind is a great way to test the strength of your premise.
Try writing something else — a blog post, an email or letter, anything — to get the mind into word mode before tackling the hard yards.
Planning is anathema to some, but for long projects especially, having a mud map of the route can provide some guidance. Flow charts, wall charts and sticky notes are useful visual aids for working out how characters and plot lines intersect, and when.
Try working backwards from the destination: for Z to happen, then X and Y must happen first.
Sometimes, you just have to butt your head against the wall. Turn off all the distractions and keep niggling away, trying different things such as changed tenses, different POV characters, and free writing. Daydreaming about the story is part of this, as you go through the combinations of cause and effect until the right one unlocks the way forward. The more immersion I can get in a story, the easier things flow, but that’s not always possible (and we all work differently), so discipline to find and use available writing time is key to getting projects finished.
Read (and broadly). Words in equals words out. Expose yourself to experience and culture to fuel your creativity.
Try starting a new scene or scribbling down some notes before you stop writing for the day, so you have a springboard into the next session.
Sean Williams, Alison Goodman, and Louise Cusack (who offers manuscript assessments) provided some of these hints during workshops and discussions. Feel free to let me know if you have methods that work for you!