Everyday aversive experiences, such as a crying infant or the sound of construction, are not life-threatening, yet they can strongly shape affective experience and physiological state. While most affective imagery research has focused on fear and anxiety, the mechanisms underlying imagery of mild, everyday aversive events remain underexplored. Across five experiments, we systematically investigated behavioral and physiological responses to aversive and appetitive mental imagery. Experiment 1 revealed robust corrugator EMG potentiation but comparatively weaker autonomic responses during aversive imagery compared with audiovisual and auditory stimulation. Experiments 2 and 3 identified key methodological factors that determine imagery potency, including imagery duration, instructional focus, and prompt design. Using an optimized paradigm, Experiment 4 demonstrated coherent changes across subjective valence and arousal ratings, EMG corrugator potentiation, heart rate deceleration, and skin temperature decreases for aversive compared with appetitive imagery, with effects modulated by individual differences in imagery vividness. Experiment 5 confirmed that these effects reflected genuine affective experience rather than semantic knowledge of the prompts. Together, these findings establish baseline physiological and subjective markers of everyday aversive imagery in typical young adults and emphasize the critical role of paradigm optimization in eliciting reliable affective imagery responses. By shifting focus from extreme to everyday aversive experiences, this work provides a framework for studying heightened sensitivity to ordinary stimuli in both basic and clinical contexts.