Nowadays, due to the constantly changing economy, employees are expected to obtain new skills and qualifications to remain in demand as professionals in the labor market. Training and coaching are the most widespread methods in the workplace for workers’ development. Although there is enough research on the group training’ outcomes, the effects of external and self-coaching are arguable and not extensively justified in the light of their high costs. First of all, it is essential to clarify the differences between these terms: training is the systematic process aimed at the provision of the specific required knowledge, whereas coaching refers to a more individual approach with continuous support. Self-coaching, in turn, follows the same methods and structure as individual coaching but without a contact person. Thus, the coaching is presumably more applicable to the development of work-related performance if the leadership style, transactional or transformational, fits the needs of coachees. Procrastination is the focus of the paper due to its high relevance for the people in different settings, including workers and students. The research on the effectiveness of the various methods to reduce the negative consequences of the phenomena is based on Kirkpatrick’s (1959/1994) four-level model of training and learning evaluation. Satisfaction (reaction), content-related knowledge (learning), goal attainment, and state procrastination (behavior) were assessed as the primary measures among the subjects in four experimental conditions: individual coaching, self-coaching, group training, and control. Transactional and transformational leadership behaviors were measured with the statements: “The coach helped me find new ways to reach my goals” and “The coach made it clear that I am responsible for attaining my goals.” The results demonstrated that satisfaction was the highest for the individual coaching and group training. Content-related knowledge consisted in scores achieved on the multiple-choice test was the best among group training participants. As for goal attainment, an individual coaching group unsurprisingly presented the highest results, though not differing a lot for self-coaching and group training. Lastly, procrastination was reduced to a greater extent with the help of individual coaching and group training. The leadership strategies were perceived as mediation effects and hence, were considered separately. The results showed that more transformational leadership behaviors were observed in individual coaching that led to higher goal attainment and satisfaction. However, the transactional style brought the same results contributing to autonomy support and intrinsic motivation. At the same time, the coaches’ transactional leadership behaviors were proved to be unnecessary for influencing clients’ experiences. Therefore, the initial hypotheses of the research were partly supported, though, for instance, the presumable effectiveness of the group training for goal attainment was not so significant in comparison with other groups. Overall, the practical implications of the empirical evidence include that both individual coaching and group training are similarly successful ways of intervention for the fight