As most of you know, my favorite two words in the English language are ‘What’ and ‘if’. They’re always linked together in my mind. ‘What if’ is the doorway to the imagination and to the start of writing a story. ‘What if’ isn’t the only thing needed however. What’s also needed is a direction for the story, setting, characters, background, history, and any other things that might be deemed helpful and useful in understanding characters or the story.
For historical fiction, the timeline during the story needs to be mapped out enough so that nothing contradicts that progression of historical events. Other stories might be follow-on to a previous series, so the ongoing characters will require a bit of their own historical research. The point is doing the extra work of researching or developing the various parts of a story help with staying consistent throughout the writing process. The neat thing is that this work is more fun at times than the writing. You get to really cut loose with your imagination and problem solving. The world is there waiting for you to make the critical links between the characters, situation, and background that propels the story forward.
Take the time to think stuff out. It doesn’t have to be as detailed as what I’ve written, but every little bit of work makes the world, and story that much clearer at the start and helps maintain continuity.