Next time you go to Starbucks for your usual Iced Caramel Macciato (or whatever your preference is), bring a notepad and a pen. This next remedy requires you to judge a book by its cover, so to speak.

Wherever you are, whether it be a restaurant, Cafe, or McDonald's, take a moment to study the people around you. Pick one person specifically (try to pick someone who is more likely to stay a while), and make a few notes about them. What is your impression of them, this complete stranger, just based on their appearance? Keep your notes simple and quick. 

And try not to be too obvious about it either, as it could easily create a rather uncomfortable situation if they realize what you are doing.

Feel free to make specific judgments about this person. What do you think their home life is like? What is their family situation, if any? Where do they live? Are they rich? Poor? It doesn't matter how accurate your guesses are in real life. The point is that you are being creative and developing a character for this person. 

Once you are satisfied with your observations, start writing about this person. Give them a name, age, and a brief description. Depending on what kind of person they are, you might want to get specific about what kind of description you are writing. For example, maybe you feel that they look like a wanted criminal, so you decide to write a short report for a criminal investigation about them and what they have done. Or maybe they look like a celebrity, so you decide to write a magazine article about his/her successes.

In the end, you will be left with a highly developed character. This will provide you with an excellent template of what a developed character in your story should look like. 

Remember to be creative! There's no limit to what you can imagine.

Here's a personal example that actually inspired one of the characters in my novels:

Titus Rivers is angry, his face solemn, the dark bags under his eyes a result of numerous sleepless nights. He is young, no older than 20, attempting to conceal his obvious aggravation.  His hair is a light gray in color, nearly white, his dark natural roots visible, long and messy, swept up his forehead as though he was caught in a wind storm. He rubs his temples as he takes a seat at the back of the room. A plug hangs from his left ear, a silver ball piercing through his nose. He squints as the sun shines through the window beside him, reflecting off of the metallic coated table. He draws the blind. Not today, he thinks.