Hi Darcy, great question and I've just posted another piece about writing a synopsis which addresses this topic. I think it all depends you on and sometimes what you're writing. I've written some before I've started, some after so it even varies from one story to the next. However, as I've mentioned in the post, sometimes if you're writing a longer story with lots of characters it's a good idea to create something even if it's just an outline before you start. Also, I'd recommend putting one together before you write if you're the sort of writer who gets lost halfway through a story or even lack the motivation to finish a story. All the best, Susan