^^^ Agree.
That said, if you want to get in front of the trend then go to your news sources and market reports. Find the tech reports. Find the recent sociology findings. Find what is happening and trending in the world. That is where the trends will originate, not from the sales numbers at Amazon. If you keep following those numbers, you'll always be too far behind the trend by the time your work is ready.
Hunger Games is a wonderful book. In an interview, she said that she wrote it because she detested popular reality television. Also, this military brat may have been tuned into drone warfare where war, even though effective, was becoming a video game gone live. The reality of death was becoming obscure, no matter how effective it is. She may have been concerned that video games were deadening our youth to the realities of death.
Her writing took on a creative flare that tuned into the 99% vs the 1% before it was an idea in most people's, researcher's and public's mindset. This past week, a serious economic report was published that began, "May the odds be ever in your favor." Science twisted back on Art or Art that twisted back on Science?
Keep your butterfly net open at all times rather than worrying about trends. That's a quote from Connie Willis.
Your trend will be all around you. I propose that the genre may be trivial or unimportant--as long as the writing is solid and addresses issues that readers are facing today.
Another possible avenue is "what isn't everyone writing about, or getting ready to write about?" Don't worry about predicting a new trend, start your own. It might fly, you might come off as being startlingly original, a breath of fresh air, etc... but you'll also risk being overlooked by those looking for what's The Now Thing. "Eh, it's not about *Insert Current Trend Here*? I was really hoping to find
more books where someone with a magic power parts shags the Elder Gods into submission, like that other series that's so popular..."
History is rich with plots, complications, conflicts and such. I'm not talking about re-writing the American Revolution, Viet Nam, or Thermopylae. Oh, look, Luna/Belters/Mars is rebelling over taxation. Been done. Sometimes quite well, other times not so much.
Rewriting old wars and conflicts has been done to death.
But we can mine for nuggets for components to mix with bits of other history we've turned inside out. There's a lot of history out there, neglected and crying under the stairs while popular culture, literature, and movies focus on Normandy, the Alamo, or the storming of the Bastille. Give that undervalued, unappreciated history some love, and it'll whisper secrets to you.
Athens started growing olives on a larger scale, which brought them into the Big Damn Merchant City stage, made them suddenly big players in the region. And this brought them a whole new set of complications even as it placed them on the road to greatness. Rome and Carthage, The Boer Wars... All examples of "underutlized" events we can borrow an element from here and there.
We can use the events when we're short on socio-political conflicts we need for a backdrop, or even just for flavoring our local history. What if the Voortrekers had become roaming nomads instead of settling the Transvaal? What if the Zulus had teamed with them against the British? What if Carthage held Rome in a stalemate, or if the two states had become allies, creating the base of a regional bloc which decided to conquer India? Or if India had joined them and they'd gone after China? Take a piece of history, tickle it until some possibilities leak out, freeze them, shatter them, then pick out some pieces to use for your worldbuilding or basic story elements.
