In a first novel the hero is often the author’s perception of himself. Unfortunately that often leads to a one dimensional character with the supporting characters being far more interesting.
I have read so many free, self-published books, entries for writing competitions, and submissions in writing groups so I can safely say you should write your first chapter with your concept of the hero and see who emerges as the most interesting character. It will be his sidekick or adversary; rarely will it be your main character.
You might say, “I’m writing a thriller. It’s so exciting I don’t have to worry about developing my main character because so much happens there isn’t time to dwell on his personal attributes.” Not so, my friend. How your hero reacts to situations is based on who he is, where he came from, his experiences, his fears, and his desires.
The memoir writers must explore their own character as they write in order to create interest for the reader. “I grew up here, spent ten years in a foster home, was beaten by street thugs, and met the man of my dreams when I was twenty,” tells us what happened but does not draw anyone into the soul of the author. “The first year in foster care, I bonded with Phoebe who was my age. At night we huddled together in a twin bed, our flimsy nightgowns scant protection against the cold in that massive Victorian house. An older boy, Tim, who was at least ten, snuck an extra blanket into our room one night, and we had a hero forever. I stopped crying myself to sleep, some nights even forgetting to pray for Amanda and John.” (I know snuck isn't a word, but the little girl used it.)
Needless to say romances and mysteries require characters with depth of feelings and emotions. Even hard-boiled detectives have a soft spot for something.
Look at your characters’ bookshelves, the décor in their homes, the clothes they choose to wear in public and in private.
Why does Lady Jane always wear a hat? Why won’t Agatha wear shorts and expose her lovely long legs? Mark has the look of a madman with his unruly toupee; why doesn’t he toss it and be his own true bald self? Sandra is myopic but won’t wear her glasses in public. That could make her miss an important clue when her stalker passes by carrying a shopping bag from what store?
There’s a reason writing books include character charts several pages long. When you fill one out, you’ll know more about your character than his height, hair and eye color, weight, and age. You will know him inside out and will be able to write an interesting character for me – ahem – your readers to enjoy.
Veronica Helen Hart Ronnie) wrote several dull characters before finally creating a few people with traits publishers liked. Janice is a spoiled California girl in the late 70’s when she is forced to survive on her wits in a foreign country in Escape from Iran; Elena, (Elena-the Girl with the Piano) a piano prodigy, runs into trouble as she escapes from Leningrad with her parents in 1943 on a trek to Germany. Elisabeth Ackert (The Reluctant Daughters) seeks revenge against a United States Senator who is planning to run for president of the United States in 1900. Doll Reynolds surrounds herself with a delightful bunch of characters as she treks about the world bumping into murder and mayhem in the Blenders Series of books which begins with The Prince of Keegan Bay.