The fewer parts, words, methods, motions, energies or other diversities and the least amount of change to a system seems to be the most effective way to solve issues. I would say simplicity would be the best choice when solving a problem.
Duane Griffin's Problem Solving Experience:
I was a member of the team that drove a vehicle that was powered solely by hydrogen across the USA for the first time traveling from the Atlantic coast to the Pacific coast. Solar energy was utilized to generate electricity which in turn produced hydrogen from water. The hydrogen was then compressed for the purpose of powering the vehicle.