At first, they may be reluctant to talk to me (oh, no, here’s another nutjob), but when I explain who I am, what I need, and give them a hint at what I’ve come up with so far, they open up. I explain that I want to be as accurate as possible so I don’t look like an idiot. Plus, I always acknowledge them in the book.
It’s important to know and understand the profession you assign to your characters. What is their everyday routine? What is definitely out of the ordinary? What about their job do they love or hate? People want to read more than the surface of the characters they are going to spend time with.
Where is the story taking place? Is it a real city/state/country? Or have you created a place that lives in your head? Are you on another planet, in another dimension or creating an underworld?
Wherever the story takes place, it requires a solid description that paints a visual picture the reader can see in his head. It has to open up and capture his imagination so he wants to turn the page. If it isn’t anywhere near believable, or they can’t see the world you created, you have failed to provide one of the above mentioned things.
Writers should never be afraid to explore all aspects and depths of characters, environments, or possible scenarios. Bring it on! Give the story teeth. Your reader will love you in the end.