From the moment we wake up in the morning to the moment we go to sleep at night, we are almost constantly making decisions. From the simple, such as brushing our teeth before bed, to the complex, for example planning our retirement, decisions play an important role in our daily lives. Despite this, it is not very often that we take time to think about how we go about making our decisions in order to achieve the best possible outcomes. This paper explores theories which attempt to describe the ways in which we make decisions. The first two sections explore economic decisions made at the individual level. The next two sections explore decision making in a more macroeconomic context. Finally, the paper ends with a section that introduces certain aspects of game theory and explores two macroeconomic games.