Characters are the stars that everything else in your story orbits around: the plot, the dialog, the details, the themes. Even “show don’t tell” is all about character. Characters are central to what we writers do every time we apply pressure to those keyboard keys! And our goal is to create real people (in memoir too) who live on the pages, act in ways the reader believes and whom the reader can care about.

But there’s something else. A character must convince us that he or she is real, and he or she must surprise us. We aren’t going to care about flat, predicable characters.

Flat vs. Round Characters (Thanks to E. M Forster!)
When we read, we focus in on characters, whether or not we realize it, and we see them as human beings with all the features, attributes, foibles and peccadilloes of a real person: black curly hair, size six shoes, a limp, a history, memories, an aversion to clowns, hair trigger tempers, hopes, dreams—although we may not read about all of these things, a (main) character has ‘em and the reader can feel the character breathing on the page. If she doesn’t, the character is flat, lifeless, and not believable.

Not to say a flat character isn’t allowed. We want a few flat characters in our work. These are stereotypes. They act in a consistent and prescribed manner. They lack complexity. They serve cocktails in the Beastly Bar. They rat to the teacher, putting our protagonist into hot water. They might be a loving mother or an evil boss, but they don’t surprise us and we, as readers, don’t care about them.

The round character is the opposite. He surprises us with his passion for reptiles, or his kindness toward foreigners, or his caustic eye on the world. The round character might be our friend. Something to keep in mind, the round character doesn’t need to be likeable, just compelling! E.M. Forster says, “if a character never surprises us, then he or she is flat; if they surprise but do not convince us, they are only flat pretending to be round.”
(Gurov in Chekhov’s “The Lady with the Little Dog” is a round character.)

Some tips for creating compelling characters:
~Be specific, particular and precise when writing character. Real people don’t act in general ways. Your flat character may cry at a wedding along with half the guests, but your round character is going to surprise us.
~A round character will not act consistently, nor will she act crazy, all the time.

Strive for complexity. Humans are multifaceted, unpredictable, and infinitely interesting!

Carolyn See in Making a Literary Life: Advice for Writers and Other Dreamers
says, "Until the rest of us have time to sit down for cucumber sandwiches [like E. M. Forster--Ed.,] there are other ways to look at the characters who are going to be important in our lives and our work." Here's how:

Make a list of the ten most important people in your life. "Without thinking about it, or trying to make a good impression on anyone, or a bad impression either. Whom do you love? Who betrayed you? Whom did you betray? Who drives you nuts? Who's out of your reach? Who's your role model? Who's your benchmark for insanity?" Write the list. Now, quickly, write the list of the "other" important people you knew and why—the ones who creep you out.

These are your characters. Carolyn says, "...the ones you know something about. You may even have said to them, in a quarrel, 'I know you better than you know yourself!'...But they give you—in a form of cosmic refraction—unique access to your own soul and vision of life."

Save your lists. You've got work to do!

Adapted from: Alice LaPlant, The Making of a Story, A Norton Guide to Creative Writing 2007 and Nancy Kress, Characters, Emotion & Viewpoint, Writers Digest Books, 2005 and Carolyn See, Making a Literary Life: Advice for Writers and Other Dreamers 2002