When we strive for long-term goals (e.g., healthy eating), we may initially be able to resist short-term temptations (e.g., cake). However, this resistance has been suggested to deplete self-control, causing us to let ourselves go when confronted with another temptation. Based on this notion, recent research suggests that instead of investing more effort in controlling behavior, people benefit more from effortless control strategies, such as the formation of good habits. For this purpose, we aim to investigate how habits develop over time, and how habit formation relates to both trait and state self-control. To test the relation between habit formation and self-control, we conducted a longitudinal study in which we tracked habit formation “in the wild” (i.e., via a smartphone app in a community sample). Participants could choose which habit they wanted to form based on 60 preset combinations of behaviors and contexts, covering health, interpersonal, financial and ecological domains (e.g., eating fruit when having breakfast, being patient when talking to someone, saving money when in the supermarket, or recycling when tidying up). Results of the current study will allow us to determine to what extent habit formation may enhance self-control, such that self-control becomes “a piece of cake”. Also, we may identify factors that facilitate or hinder habit formation, which may serve as input for self-control interventions.