Some just pop into my head at random, which is no help to anyone. Others start with a stray piece of information that sticks and after lots of thought the concept comes together.
Every time an editor accepts a story I shall describe where the idea came from and how it develops. I thought it might help with the answer to the ideas question.
In April 2014 my SF short A Bit of a Mutiny was published by Jupiter SF in issue XLIV.
It took two years to write despite being around only 4,000 words long.
The IdeaIt started with me discovering the largest human creation on the Earth is the Pacific Trash Vortex, also known as Great Pacific Garbage Patch. It is where the currents of the North Pacific sweep rubbish into one massive area of plastic pollution. It is nominally the size of Texas and estimated to be millions of tonnes of rubbish. Some of it is large like plastic buckets, toothbrushes and packaging, particularly carrier bags; however, the majority, and worst of all, is the stuff that has partly degraded into microscopic particles the size of plankton.
This stuff washes up on beaches, gets eaten by mistake thus poisoning or choking unlucky creatures and slowly, but surely, permeates the sea at every level. Hey, if you've eaten some Pacific tuna you too may be ingesting some plastic from the Great Trash vortex - now that's a thought.
There are similar collections of pollution in other oceans, but this is the biggest. I live near the sea and see the junk that turns up on the shoreline dumped off ships or pumped out of sewage outlets. I hate waste and that is how the story started: how do we clean up this mess?
This lead to the idea of a titanic machine slowly struggling with a lifetimes' work of purging our ocean. Even if the governments of the world argue over who's at fault and who should clean it up, it is still our ocean. Everyone of us, every human living and breathing has a stake in it and I say that living as far from the Pacific as it is possible to live.
Any way, I wrestled with the 'what's the stroy?' problem. Cleaning the ocean could be a whole novel, it could be a very boring one too. I mentioned my vision of this huge ship filtering the sea, gathering junk at all levels to friends and family members. They said, apart from idealists, who would ever bother with cleaning it up and idealists rarely have the money to do it.
Money, that was the key, governments suffer when they build ambitious and expensive projects because there are always people who think it's a waste; for example: pacifists paying for the defence of their nation, childless people paying for schools. No government would pay for cleaning up the sea that wasn't 'their problem'. Then I saw my government were announcing their latest budget, giving tax breaks for this or that to encourage less selfish behaviour of the rich.
What if investors in a cleaning-the-ocean machine received massive tax-breaks. What happens when those tax breaks are taken away? Suddenly the story came: idealists running ship, having dedicated their lives to healing the sea, facing off assert strippers keen to max their profits. The prize being the largest ship in the world. Hey, this is science fiction, it had to be didn't it?
So the story is a battle, a clash of two different sorts of people, using all the weapons - some surprising - in their arsenals to win. What's at stake? Nothing bigger than the health of the largest ocean.
So that's how the idea for A Bit of a Mutiny developed.
Useful LinksJupiter SF
National Geographic's Web Page on the Great Pacific Garbage Patch
Lies You've Been Told About the Pacific Garbage Patch
Why is the world's biggest landfill in the Pacific Ocean?