My favorite of all the "secrets of social innovation" is Dave Tait
's "Think creatively:
start big, use constraints as a filter and find the simplest solutions." This statement includes all the valuable points for any problem solving process.
There are always big issues for human civilization to deal with, which often gets lost in the day-to-day grind of maintaining ordinary life. There are many issues that must be dealt with by humanity as a wh***, as well as individual nations. However, when it won't be a real concern until the next generation, or today's issues are given more importance, they lie dormant until the crisis is upon us all.
That being said, when grand solutions are
considered, they ignore constraints from a variety of sources -- technological, social, political. Nuclear fusion may "solve" the problem of energy resources, if it ever actually works... going on fifty years of research! Is genetic modification of humans a positive step towards a higher goal, or an abhorrence with many ethical problems? You have the best solution to problem X, but you ignore the fact that it effects the wallets or ideals of group Y... and they're a majority of the population.
Finally, simplicity has an elegance all of its own... but it also helps convey and propagate change. Ideas reducible to one sentence, or objects made from a few odds and ends, can spread much more rapidly. If people can do it themselves, and they see the benefit of doing so, then it will be done.