We examined predictors of subjective well-being (SWB) associated with do-it-yourself (DIY) activities in a sample of 525 self-identified DIYers through Amazon's Mechanical Turk. We hypothesized that positive mood, feeling energized or aroused, and experiencing flow during DIY activities, would each contribute to subjective wellbeing (SWB), and, that negative self-focus would not. We also controlled for individual differences that could affect the experience of negative self-focus and flow: quiet ego and depression/anxiety. Overall, participants identified most with DIY activities that involved aesthetics, repair, upkeep and maintenance, and landscape or gardening, and construction; they reported these activities were challenging and utilized their skills. Using structural equation modeling, we examined our hypothesized model and two alternate models. Our amended hypothesized model accounted for 61% of the variance in SWB. Positive mood/arousal was positively associated with SWB. Quiet ego facilitated SWB, both directly and indirectly through the positive mood/high arousal pathway. Depressed and anxious mood was negatively associated with flow during DIY activities and SWB; it was also positively correlated with excessive self-focus during DIY activities. Our results lend credence to the idea that DIY activities that induce positive mood and high arousal may benefit SWB. Having a strong quiet ego identity may enhance the benefits associated with DIY activities. Our study contributes to the literature by describing the mechanisms responsible for how DIY activities promote SWB, as well as by explaining the factors that optimize the impact of these experiences.