"Where do you get your ideas?"
This is of course the classic eye-rolling writer question. In speculative fiction, the question can run much deeper than it does in other genres. There are as many ways to address this with serious intent as there are writers to address, but we have chosen two main aspects to emphasize.
The first aspect of this question is a matter of definition. What is an idea? What does it even mean to have an idea? Most importantly, what makes an idea SFnal, or fantastic?
In this context, we will posit that an idea is the root concept from which a finished narrative develops. The depth and detail of the idea vary widely from writer to writer, as does the degree of effort required to coax a story forth from the idea. The origin of an idea differs for each writer, and even for each idea. If your conception of an idea is as a sort of seed or stub, then they are literally everywhere waiting to be picked up, like shells on a beach. If your conception of an idea is a more developed realization of a story, then ideas are complex beasts which must be fostered into being.
Jay: For me, something as simple as a word, a memory, or a visual image can be sufficient to stimulate a story. One of the most direct examples I can think of is my story "Tall Spirits, Blocking the Night." At a workshop reading, I misheard another writer's line, "tall spirits, walking the night," as "tall spirits, blocking the night." I walked around for some days with that in my head, alternately enchanted and frustrated, until (with permission from the other writer) I built a story around a literalized reading of the line. "Writing until it made sense" is the best I can do to describe that process. The idea which gave rise to the story was nothing more than that line, and the images it created in my head.
Ruth: It's true, ideas can come from all kinds of inspiration, but what gives rise to a story for me is when several ideas come together in some unusual way. One example is my story "Dragon Time," published in the anthology Fantastic Companions. I was in a bit of a frustration phase for one reason or another, and I decided I wanted to write a story for me, a story about a gal who gets to live her dream and gets the guy thrown in for good measure. So I sat at my computer and gazed around my desk, at the dragon mobile hanging from the shelf, at the various cool Swatches scattered around the keyboard and started to try to figure out how I could get dragons and timepieces into one story. I asked myself a few questions, and soon I had the basic framework.
Then there are the pieces we've written collaboratively. We've sold a number of stories jointly, to SCI FICTION, Realms of Fantasy, Baen's Universe and others. Those ideas can follow an entirely different path. Take for example our story, "Schwarze Madonna and the Sandalwood Knight." We've been working on a series of collaborative stories in the world of the the Rose Knights for a while now, so the worldbuilding was largely a given. Some of the initial inspiration for the stories is defined as well—all of the main characters bear the names of real roses. Ruth began the story with the tale of "Schwarze Madonna," a rose of such a dark red that before it blooms, the bud has an almost black sheen. She passed this beginning on to Jay and asked him if he wanted to add the story of the farmer. After being passed back and forth a few times, and adding a few more roses, it became the story which appeared recently in Realms of Fantasy.
As for the question of what makes an idea SFnal or fantastic, this is one of those propositions which is simultaneously obvious and tricky. In a basic sense, a story told in the Western tradition has a character in a setting with a problem, who makes multiple unsuccessful attempts to resolve their problem until they achieve resolution. (There is also usually a validation scene.) An idea, in the obvious sense, drives one or more of those story elements.
One can also think about ideas from a perspective of craft techniques. A writer might seek to write a story in a certain voice, from a certain perspective, with a certain structure. In doing so, they seek an idea which maps to that effort, rather than an idea which drives a story element. Same process, different axis-of-thought.
What makes an idea SFnal or fantastic is adding a third axis-of-thought, the genre device. This is what drives the skiffiness of a story. Defining the genre device turns out to be an elusive quest, leading readily to circular reasoning, or a veritable forest of exception cases. The classic Potter Stewart definition, "I know it when I see it," seems to be safest in the context of the current topic. Essentially, the genre device moves an idea out of the realm of the naturalistic and into fantasy or science fiction. (Or, presumably, erotica, nurse romances or what have you.)
An idea can come from Schenectady or the pile on the desk, the conscious or the unconscious, guidelines for an anthology or a misunderstood phrase. What is important is to be ready for ideas, to watch and listen and remember—and play. Like whelks, they must be teased from their shells.
The second aspect is developmental. Once an idea arises, what happens to place it in the writer's mind? Once an idea is in place, what is needed in order for the writer to transform it into a story?
Jay: As I have already mentioned, ideas can come from anywhere—a phrase, the position of a shadow on a wall, a photograph I have taken. Ideas are the cheapest part of the process. Since I only need a tiny stub of an idea to get from there to a story, I can derive it from anything. One exercise I've done when working with kids is to have them point out three or four items in the classroom, then immediately give them back a quick story idea based on those elements, just to show how easy this is. The story comes from the juxtaposition of those different objects, by looking at them in a new light, in connection with each other.
Ruth: That's much like how I wrote "Dragon Time," when it comes down to it. I think most writers would agree that ideas are all around us all the time, and seeing those opportunities is part of what makes us writers. How the ideas evolve into story, now that's a little more difficult. Some writers, like you, can take the barest hint of an idea, and can sit down and make a story out of it—all you need is a little consultation time with Fred. For me, that's just about the surest way to write myself into a corner. The evolving phase for me usually requires pen, paper, couch, and a lot of questions.
In writing together, we've found that working from a set of guidelines can give us a joint springboard for developing an idea. In the case of "Return to Nowhere," we knew it would be in Jigsaw Nation, an anthology of stories about an America where the red state/blue state divide was literalized in some fashion. This led us through a collaborative brainstorming process into which various political maps figured, including the so-called "slavery map," and we wound up with a story about an America where slavery was never abolished.
Going from idea to story often involves some kind of brainstorming session as described above. If the first germ of a story is a particularly evocative setting, it must be populated by characters who will give the setting meaning. If it is an article in a newspaper that suggests a plot, perhaps the speculative element needs to be brought in. If it is a technological development that suggests promising complications, the writer needs to figure out who will be hurt by it. This process can take place consciously or unconsciously, but on some level, the writer begins to develop the elements in which the original idea will be embedded in order to create the story.
No matter what the process and the idea-product, the writer must have a sense of creativity and openness. If you are not in a position to be receptive to an idea, it isn't going to arrive. This is perhaps something like searching for signs and portents. Your eyes must be open. Some writers use a hypnagogic state to reach their ideas—reaching into the field of dreams. Some writers use the discipline of process—sitting down with their blank sheet at the appointed hour. Some writers use a second path of creativity—practicing art, music, photography to feed the wellspring. In short, ideas can come from literally anywhere, and they can lead literally anywhere. Definition and development do not matter so much as the process by which writers nurture their ideas, bringing them from whatever origin point best suits them through the stages of development before arriving at a story.