First of all, this is a link to examples of last round's writing prompt finalists. So if you're interested in entering this round's writing prompt contest, check that out to get a feel for what the judges are looking for.
Let's take a look at your main character.
We've already talked about that there should be only one main character. Yes, we can probably find books that break this rule well, maybe there are even plots that require an ensemble cast. For our interests, though, we won't look at exceptions. We'll just assume one main character.
For me, my main character is the first part of the story to arrive in my head, but that might not be the case for you. You might be having trouble determining which character would make the best protagonist.
A good way to determine this is to ask which character has the biggest change to go through.
Your main character cannot, I repeat cannot be perfect. Your main character needs to change, and your story is largely about how that change takes place. It make the book satisfying.
First, determine what change needs to take place. Maybe it's something your character is aware of, or maybe it's not. And maybe there's a couple changes taking place; an outer change (like a need to live a healthier lifestyle) and an inner change (a need to be comfortable with the body they were born with).
Next, brainstorm how they can be tested. These will develop into major plot points for you. Say your character has diabetes and needs to develop healthier habits or he'll die. Will he over indulge on sweets at Christmas time? Fall in love with a pastry chef? Hate his personal trainer?
Some tests they should emerge from triumphant, and others they should fall on their faces. Which leads into the next point:
Utilize the pendulum. Ever watched an action movie where the hero is too slick? Every shot he fires hits his mark. He emerges unharmed from every fight scene. Doesn't feel real, does it? Avoid this by balancing the good and bad.
Like in Me, Just Different, Skylar nearly gets raped at a party - that's bad.
But it leads her to decide to be safer in her lifestyle - that's good.
But Eli rescuing her at the party makes her feel obligated to date him - that's bad.
But he agrees to support her new lifestyle - that's good.
And so on.
Determine a "black moment." This is a moment where your character has lost everything, including the desire to change. They're not sure if it's worth it, and even if it was, they know they aren't capable of doing it.
But then during one final test, they somehow (often with the help of others) summon the strength and emerge triumphant from the final battle. They are stronger than they were at the beginning of the book, and while it wasn't always pleasant, the journey they just took was necessary.
This will make your reader sigh with satisfaction when they close your book.
Have writing questions? Email me.