This is generic advice, so it may not be applicable to your particular situation - but this is something that's served me well in Workforce Planning and Analytics:
- Do a current state analysis - for a given topic, look at how things are today.
- Extrapolate existing trends - look at the changes that are already occurring, and extrapolate these into the future. This will identify unsustainable trends that usually mean that topic is going to be disrupted.
- Do an environment scan and look at those PEST factors (Political, Environmental, Socio-Economic, and Technology factors) that may have an impact on your area of study.
- Of the factors from point 3 above, identify the two factors that both a) have an uncertain outcome; and b) will have significant effects on what you're studying. Note that this is not a risk matrix; risk matrices score factors on likelihood and impact - here you are scoring on uncertainty and impact. A factor that's uncertain and would have a high impact, for example, would be an election result where the two parties have significantly different policies that directly impact your area of study.
- Create a grid of those two factors - and think about what would happen in the future (whatever your timeframe) in your area of interest in each of those scenarios.
- Find commonality in those four scenarios in terms of how the world would deal with each of those scenarios; and you may have some insights into future events in that space.