Along with creative titles for books and stories, I admire the appropriateness and cleverness of the names some authors come up with for their characters. I guess it probably started with Ponyboy and Sodapop in The Outsiders. Original and unforgettable. Sometimes names are pulled from history and inserted into a story to purposely push the characteristics of the original owner. Once in a great while, there is just certain poetry to the names being used which has to be admired -- Katniss Everdeen.
I strive to be faithful to the timeline of the character as well. I don't think anyone could imagine giving a newborn today the name Percy, however, it was popular at a certain time in history. Likewise, I avoid names that have preconceived conflict attached to them. Some names will carry baggage forever and distract from the story.
I can't think of a time when I purposely used the name of someone I know in a story. I purposefully try to avoid it simply to avoid the real-world conflict that might arise. That doesn't mean that I haven't been tempted to name a villain in the story after a villain from my personal life or to use the name of a high school crush for a romantic interest in a book. Like all writers, I mine my experiences for bits and pieces of stories, but I shy away from including names and places where it all took place.
Once in a great while, there is a confluence of forces that brings a name to me just when it is needed. That happened recently. My current work in progress has a character who was nameless, not an unusual situation in an early draft. Then out of the blue, I got an email about another matter and the name of the sender was perfect for the character. Yoink! Lightning strikes.