Everyone has their own way of doing things. You only have to watch two people load a dishwasher to know that.
And it’s no different when it comes to doing research for your writing. Some people like to do all their research before they write the first word. Some people like to leave a marker as they write, and come back later to fill in the details that they need to research. Personally, I like to research as I go, stopping mid-sentence to look things up if necessary.
So, what should you do? My suggestion is to do whatever keeps the words flowing.
If you can’t even think of beginning your historical-romance without knowing everything there is to know about 17th-century France, then do you research first – but not to the point that you never stop researching and start writing.
If stopping writing to look up how to tie a lasso properly means your cowboy character will be left hanging for the rest of the day, by all means come back to that point at the end of your writing session or in a later draft.
And if, like me, not knowing what the sunlight on a green hill really looks like is just going to niggle, look it up, write it in and get back to getting the words down.
Whatever you do, remember that it’s often the believable details that move a story from good to great and help the reader suspend their disbelief so that they can enjoy the ride. And their enjoyment is really what your job is about.
Where do you stand on research? Before, after or during?