You’ve made your characters real, as real as possible. From the tax accountant to the beggar on the street, you know that you can relate to everyone in your story somehow and in some way. Now it’s time to give that story some style. A way, a look, a thought that will not be forgotten.
From the serene and believable waters of Lake Tahoe to the quirky 9th world of Schakkanida, your story deserves the right form of settings as well as the style of a lifetime. This is the life of the book, what makes the reader be brought into the world that only your mind imagined.
Fantasy writers – you have this in the bag. As long as you make the situations realistic, meaning a plot that has a significant reason behind it that can be related in this “real” world, your job is a piece of cake. Not to mention, it’s a blast making up all of those aliens, seahorses, or whatever gets your goat. Though you have a job in front of you, you can also bet that when you are done, you will believe what you wrote, and so will everyone else.
For other genres, remember that you have to keep your story “real” to be believable. These are characters who count, relate, and have things happen to them that would be normal. The car broke down…too simple. How about “His 65 Shelby screeched to a halt as he heard the unforgivable release of chains under the hood.” Now that we can see.
Still using the car example, remember that there are over 10 different manufacturers of vehicles, and hundreds of models by each one. Whether it is a pick up, sedan, or even a monster truck, you will need to tell your reader what it is to make them see it just as you do. Define the car. Is it a Cadillac, used in police work? Or maybe a run down Gremlin from the 80s? How about a Scorpion, owned by the largest drug lord of Veracruz? 
Each of these define the person, the style of the story, and tell the reader whether or not you did your homework when looking. Do you know where the car came from? Is it European or Japanese or American?
The same goes with many of the details of your story. You may think that the smallest of details will be overlooked, but guaranteed, a hefty and avid reader will notice the missing links. Ensure that your world becomes theirs with the use of plenty of adverbs and adjectives to tell the world what you see.