The quest for a magic formula to success exists in many industries, but those seeking a career in screenwriting are some of the worst offenders. People flock to seminars, purchase books full of foolproof secrets, and work to drain their stories of anything that differentiates it from the current crop of blockbusters.
It's not that there aren't positive things to be learned from experts, but that aspiring writers start to believe following a specific set of instructions guarantees them success. If you're not writing a sequel with a built in audience or a remake, in short if you want to succeed with a wholly original work, then you have to come up with something unique enough to attract the interest of a cynical and media exhausted public.
It's not enough to simply have a film crafted in a proven format. To truly break through you need an idea, concept, or character so fresh and interesting that the audience is drawn to your film despite themselves. The search for a road map to screenplay success illustrates the larger issue of people not realizing that a great story is the secret to writing a script that sells.
If you are chasing a trend you can virtually guarantee that it will be obsolete by the time your screenplay is finished. If you notice that the kids seem to be going wild for vampires these days, and try to write a teen bloodsucker romance, the public will have moved on to something else by the time your script is completed. The film industry moves too quickly to chase what's popular, so you're better off trusting your own gut instinct.
If you don't believe in the stories that you know best, and are most capable of writing from personal experience, then how can you truly expect to author something successful. The most personal experiences are often the most universal because audiences relate to truth, and have a keen sense of fabrication. Even if your story is pure fiction, having that level of personal truth ingrained will make your movie much more appealing then a transparent attempt to craft your film around whatever is popular at the moment.
This may all sound a little idealistic, and in some senses it probably is. There is a good chance your unique script that weaves in the truth of your own experiences will still be rejected. However, this does not mean that your Transformers Vs. Godzilla idea would have been successful either. In the end the odds are stacked against you either way, but if you come up with something that hasn't been seen before you might have the slightest chance at success.
A unique story will at least stand out among the hundreds of other story-by-numbers scripts sitting on any studio's front desk. So instead of being sucked in by the newest formula for writing a screenplay that sells, focus on what makes the stories you have to tell unique. The emphasis on making your script fit into a mold that was successful in the past could be what prevents you from selling your script in the future.