It’s hard to write main characters that are strong and likable. Agent Linda Epstein’s blog had a recent guest post who addressed this particular problem and it struck a chord with me. I’m sharing the part of the post that I liked down below. For the rest of the article, you can read it here. (Highlights are my own.)

“According to the Transitive Property of Reader-Character Relations, readers will echo the reactions of characters they already know and like and/or trust, and oppose the reactions of characters they don’t like or trust. Consider the opening of Harry Potter and the Sorcerer’s Stone. The Dursley family is shown to be amusingly small-minded and aggressively normal, so we readers enjoy feeling superior to them. But we also learn the Dursleys hate the Potter family for being so different, and since we dislike the Dursleys, we automatically like the Potters—a useful first step in making readers sympathize with Harry. Think about how your character math works as you introduce new figures into your book.

You can also use supporting characters to create more dimension in a character who thus far has had only one identity.

In the woods waits the only person with whom I can be myself. Gale. I feel the muscles in my face relaxing, my pace quickening. . . . The sight of him waiting there brings on a smile. . . .

“Hey, Catnip,” says Gale.

—The Hunger Games by Suzanne Collins

In the first six pages of The Hunger Games, we see that Katniss loves her family, but she’s not a particularly kind, enthusiastic, or pleasant person. Then she goes to meet Gale in the woods, and this happens: She relaxes. She smiles. She experiences pleasure in someone else’s presence, and Gale likes her as well, which confirms Katniss must have some warmth we haven’t seen yet. That affirms our own interest in her and maybe even warms it up to affection, and that makes us extremely invested in her when she volunteers for the games at the end of the chapter.

A corollary to the Transitive Property: Readers like characters who are liked by other people. They are suspicious of characters who aren’t liked by other people. If you’re writing premise-driven fiction, consider giving your protagonist friends right away, because the friends provide an instant affirmation of the worthiness of the reader’s interest in the protagonist. With that interest confirmed, you can get right on with the plot.”