You would think writing about a time in the future would be easy. At least, I did when I started.
Hack the Yak, my first novel, is set in 2049-50. I originally conceived the story while worrying about what is going to happen to medical care, given the ability of the political system to hose up even seemingly simple problems. To talk about the result I dreamed up, I needed to be in the future. Along with the future came the (I predict inevitable) cyberwar and the (also predictable) highly secure Internet follow-on with a (predictable) kluge of a name (InterAgency Communication Channel) that became ‘the Yak’ in common speech.
My future world is not dystopian, and that makes writing a little more risky than if I could create a world out of whole cloth. No gloom and rubble populated by tribes of bloodthirsty criminals whose parents were osteopaths and lawyers back in Ashtabula before the bombs started falling. I’m guessing forty years from now, give or take, will be pretty much like forty years ago compared today … considerable technological change, but very little change in the emotional dynamics that rule our lives. So in 2049, computers have become ‘repeaters’ (because most data is in what we now call the Cloud). iPad-like computers are ubiquitous and are called simply, pads. The ‘hairball coughed up by Congress’ to control medical costs looks distressingly like the current FICO score that controls our finances. Car ownership topped out somewhere around 2020 as public transportation became more and more appealing and ubiquitous. Single vehicle use is now falling, with computer directed hybrid vehicles dominating and the most popular car a very small three- or four-wheeler generically referred to as a ‘mono’. There was a brief flowering of commercial drones in the 2030’s when new airspace software and really good robotics made having thousands of unmanned vehicles in the air over a city safe, but it was squelched quickly as entrepreneurial spirit drove its use to illegal and unconstitutional activities. 
I’m guessing that we won’t have done away with cash by 2049, although the great bulk of legal business is done electronically by then, and my protagonist Joe has to pick and choose out of the way places in order to live on cash while he tries to evade the thugs that are sent to make sure he doesn’t spill the secret of the software called Phoenix.
In the end, 2050 looks a lot more like today than most so-called speculative fiction would have it appear. That causes a classification problem: at least to me, speculative fiction written a generation ago … 1984, A Clockwork Orange, Fahrenheit 451, several Kurt Vonnegut stories … speculated more about people and institutions, whereas current speculative fiction seems to concentrate on dramatically different settings (The Road, Hunger Games). Hack the Yak is closer to the first camp. I’m not allowing for a nuclear breach or dramatic changes in weather. Love, friendship, courage, greed, sadness and music are unchanged forces. I guess that means I’m an optimist.