This terraform keynote by Michio Kaku addresses the possibility and of creating human societies on Mars. From this, he offers the most efficient and cost effective way to do so.
Michio begins his terraform keynote by stating it would likely be centuries before humanity is able to terraform Mars, but he still offers how it would be best made possible. He shares that Mars has carbon dioxide that just needs to be harnessed. In order to do so, the process needs to be kick-started by warming up the temperature of the distant planet.
Many theories have been proposed including using a nuclear power plant and hydrogen bombs. This will start a chain reaction of creating enough carbon dioxide to eliminate the need for bring carbon dioxide pumps and machines.