There is a great deal of misunderstanding about what that particular branch of literature called Science Fiction actually consists of. Is it space-ships and monsters? Time machines? Galactic empires? Well, its all of those things, and often none of them.
Science Fiction, broadly speaking, is story-telling that deals with the impact of organized knowledge on human beings. Usually, this means technology, and the way it changes usand reveals about us. After all, most technology is an extension of our senses, attributes and desires: computers are brains, cell-phones are voices and ears, cars are legs, planes are the dream of flight.
Many classic S.F. films and books take place in worlds identical to ours, except for the creation of some new device, or the appearance of a new life-form. Others take place in worlds so apparently foreign that only the most dedicated and experienced reader can understand what is going on!
But at the core, there are three questions or musings most often asked or explored in any work with the Science Fiction label. Those three are:
1) What if?
2) If Only
3) If This Goes On
Although these three “questions” overlap considerably, the first, What If?, is the most essential of the three. What If the Martians attacked? What If eternal life was available at a price? What If we knew an asteroid would hit Earth in a year?
The second adds a bit of longing to the equation. If Only President Kennedy hadnt been assassinated is the kind of question that leads to sociological and historical speculation, or the Alternate History branch of S.F. which has become tremendously popular in the last decade. If Only the gene for generosity (or anger, or bigotry) could be mapped If Only we could selectively prune bad memories
There is an emotional quality to the If Only questions, and they often speak to a sense of missed opportunity, roads not taken.
The third question, If This Goes On is tailor-made for cautionary tales. If we continue to pollute the environment If one party continues to dominate American politics If more women enter the management class If the space program continues to Privatize If human beings become better at modifying their physical characteristics
These questions are starting places for speculation. While it is easy to use any of them for trivial or absurd (and entertaining!) questions like What if a 300-foot radioactive lizard attacked Tokyo? they can also address profound issues, as in how would humanity change if we gained incontrovertible proof of intelligent alien life?
By concentrating on the question, or proposition, at the core of your story, it becomes easier to keep it from becoming a CGI-fest. Ask yourself how YOU would react to a given situation. How your family would reactyou know them well. Then friends. Political adversaries. Other nations, and people of other groups. Dig into the meat of it. Study history, and begin to grasp the way societies change in response to technology, for instance the Automobile, or Printing Press, or Computer.
The more deeply you delve, the more likely you will be to create a unique question with unique answers. Then people your world with breathing, believable characters responding as intelligent, feeling people have since the beginning of time. Your work will blossom and reach new levels
Even if it IS about a 300-foot radioactive lizard!