Writing a fiction piece can be an overwhelming process. There are so many things to take into consideration. One of the many choices you have to make is where is this story going to take place.
In many cases authors write stories that take place in their own backyard. They may fictionalize it a bit, but the location is very clearly where they live or place they have lived. Some writers are not too impressed with the options they know. In those cases you can either make up a fictional location, or you can choose another city or geographical location.
While it does help if you have been to the location you choose, that is not a prerequisite. The internet has made doing research on locations pretty easy. A few simple Google searches can lead you to all the information you need. That being said, you still need to take your time and make sure all of your information is credible and that you have all your bases covered.
My goal is to have it so if person from San Francisco reads my story, they will believe my location is in fact their city. While everything may not be spot on (some items I won’t get just right, or I may take some creative liberties, overall it matches up their reality.
First I look at the city itself. I look at how the city is set up geographically. Then I focus on the neighborhoods. Who lives where? What are the real estate costs? Do people own or rent? What does the architecture look like? What is the cost of living? What kind of jobs does the city have, and what are the average salaries? What is the overall style f the city? What is the overall style of each neighborhood? It is good to have a street map of the city. That way you can figure out how to get from point A to point B. If you characters will be using public transit, of map of those routes will be helpful too. If you character is all about shopping, what are the shopping musts? If part of your story will focus on the nightlife, what kinds of clubs are in the city. Do certain neighborhoods house particular types of clubs?
By knowing these details, you can easily fill in the blanks as you write. While fiction is made up, suspension of disbelief will only take the reader so far. It would be hard for anyone with an idea of San Francisco’s cost of living to believe an up and coming photographer owns his own Queen Anne Victorian in Pacific Heights. Now if that same character was left that house and a sizeable inheritance by his grandmother, and he also rents out one of the spare rooms for extra income, it becomes more plausible. A social worker for Hospice probably rents, and if he lives alone the apartment is a studio or a very small one bedroom at best. Giving him anything more spacious would not add up.
It may seem nitpicky, but knowing these little details can help you writing. By taking your own made up ideas and merging them with reality you are helping your reader create a clear picture. That is the goal anyway, right?