Decision making is a critical skill throughout all echelons of the military. From command and control to the front line, Warfighters must be trained to quickly and effectively make decisions. Key to the development of effective decision makers is the utilization of targeted learning strategies, designed to improve an individual's decision making process. One such strategy is process level feedback, which provides information regarding how effectively an individual is utilizing task strategies or performing task sub steps necessary to achieve task goals. Process level feedback can be employed to improve decision making skills by identifying and correcting breakdowns in the decision making process. A process level feedback method to target decision making skills was developed for use in simulation-based training. This feedback method incorporates outcome feedback with process level feedback aimed at decomposing decision making performance into sub-processes using the OODA loop as the theoretical model (Observe, Orient, Decide, Act; Boyd, 1987). Feedback is provided on errors/error patterns across these sub-processes. This feedback strategy was evaluated in a series of experiments conducted both in the laboratory and in the field with Marines. In the laboratory study, participants who were recruited from the community performed tactical decision making tasks in a simulation testbed and either received the process level feedback or a control condition of outcome feedback. A similar study was conducted with experienced Marine Corps squad leaders. Marines at the School of Infantry East received training utilizing either a simulation-based training approach which incorporated this process level feedback method or simulation training with methods traditionally used in the Marine Corps. This paper will describe the process level feedback method, present results of both experimental studies, and discuss implications and lessons learned for implementing this method in a military training setting.