I don’t think you can really be a writer unless you are also an avid people watcher. I really like to sit with a coffee and watch the people around me. I don’t write stories for them, I just observe and come to my own conclusions about who they are, what they think and feel. Do they seem tired, grumpy, cheery, clever, amused, interesting, rushed or laid back? Are they well dressed or a bit too casual? Does that hair style really suit them? You can go on forever.
What things do you see that cause you to decide who someone is, on one sighting alone? I think the way they dress, their body language and how their face, are big first impression tip offs. Next time you are people watching consider the first three things you notice about people. Do you notice different things than I do?
Do you write that way? When you describe a character do you write about them as if they were someone you just saw at the mall, in the parking lot at work or wherever you happen to be writing them. Do you give details about their appearance, body language and facial expressions?
Have you ever written about a stranger you watched somewhere? Try it. Give yourself a challenge and write in a different venue than your usual. If you write fiction try poetry, if you write non-fiction try fiction and so on. Go nuts and write a greeting card just for them!
Most of all, keep watching those passers by, you never know when they will become inspiration.