Vulnerability has been shown to be a great way to get readers to sympathise with a character.
Those who are in a predicament must try to get out of trouble, and this gives readers the vested interest to read about a fictional person they otherwise would not waste their time on if they had no problems in need of rectification.
Despite the fact that there are only so many truly original story ideas out there, the number of ways they can be interpreted and mixed at varying volumes the way one would when adding the exterior decoration on a pastry are about as unlimited as the atoms in the universe.
Therefore, try not to worry so much about making a story unique.
Focus on making it personal.
And the best way to do that is to make yourself as exposed to potential ridicule and criticism by your audience as your character.
This would mean looking at your inner self and wondering what you would do in a given situation with self-critical honesty, and applying this to your story.
Not only does a realistic mindset reduce the chances of creating a wooden and unemotional plot, but knowing your strengths and weaknesses in a given situation, and exploiting that for your audience produces a form of humility that will make you both sympathise and empathise with your creation as much as you want the readers.
Even though we hear all the time about not writing a ‘Mary Sue’ character, it must be stressed that when it comes to writing, the same is applicable to writers, who must insert a part of themselves into a story, whether they do so consciously or not, in order to gain maximum effect.
You may find yourself writing action stories with background themes that might make you less comfortable — such as your main character making humorous statements that may fall flat with some of your readers, or their outer shell being weakened by developing feelings for another character — but the positives for these risks is that even if some audience members will not appreciate this, some will.
And what is the reward if you choose to play it safely and not subject your shortcomings to your character?
You may not be excoriated by some readers for adding all that “fluff”, but those who would otherwise have appreciated such effort are also not going to have anything positive to say if you create a one-dimensional character who fits your imaginary — as opposed to realistic — idealism.
In conclusion, I would recommend thinking deeply about your character.
Who is he or her?
What do they look like?
How old are they?
What would they do if they were with you today at a restaurant, shopping mall, or movie theatre?
Even if you think it is “silly”, spending some time with your creation in a real setting, and imagining their reactions and comments will make it so much easier to map out their story arc on paper, which in turn will pave the way for a workable plot that would otherwise never function to its full potential until you begin acknowledging your imperfections into your own written creation.