Since my three novels are all historical fiction, the first project is always research. I love it, I could stay with the past forever. It’s there to be figured out, to be understood in a comprehensive way. The present is too muddy, too blurry with situations that have not become clear as yet. And the future, too scary (especially in our present climate.)
But the big question is always, when is enough research too much, so seductive you don’t get back to writing. The creation of your story, your characters and their world is the most important. Once you have investigated a foundation of the times and places for your book, get back to writing. You will continue to research, even one detail at a time if necessary. When I decided that my protagonist in WHERE DO I GO, could be a healer with natural herbs, I had to go back and study which herbs grew in her area and what their healing effects were. Did they have ice cream then, research. How about cooking methods, research. Anything to enhance the times, but also what would enhance the story and their character. At that point, doing the research gave me a break during my writing day and still didn’t detract from time spent.