Systems thinking is a way of understanding systems as wholes, as well as the ways in which independent parts interact with and influence the other parts of the system. To get started you just need to start thinking about the systems you’re working with, or designing, with this new lens. What are the inputs, processes, & outputs? Are there any undesired outputs (negative externalities)? Are any of the inputs hazardous, or in short supply? Could hazardous inputs be replaced w/non-hazardous ones? Could virgin materials be replaced w/recycled ones? Could different processed lead to increased benefits/reduced harms. Any time you consider changes, run the updated system through your mind repeatedly & look for unintended consequences.
Systems thinking can be used in problems solving, & problem prevention. By designing with systems thinking in mind, many unintended consequences can be avoided. And in considering alternatives, benefits that would otherwise have been missed, might be realized.