During our lives, we are constantly affected by situational cues that trigger habits and impulsive reactions, even without our conscious awareness. Although these cues often help us during the self-regulation process, in many cases they undermine our efforts to regulate our behavior and emotions, which can negatively affect our health, well-being, and performance in daily tasks. In order to help users improve their behavior or regulate their emotions, several self-regulation technologies have been proposed. However, existing technologies often require constant engagement and effort from users, which add significant barriers to their usage. In this dissertation, I present a new approach for designing self-regulation technologies by focusing on how people automatically and mindlessly react to situational cues. I also describe the design and evaluation of mobile technologies developed using this approach, including a watch-like device that can decrease user’s anxiety; a voice modulation intervention that can reduce anxiety during interpersonal conflicts; and a smartwatch application that can decrease user’s arousal and improve their cognitive performance.