To improve decision-making skills, two things need to happen. First, you have to make decisions that challenge you and force you to work hard. If you never make decisions that you find difficult, and if you are rarely wrong, it's time to ask your boss for more responsibility. Second, you have to pay attention to the outcomes of your decisions and evaluate, with the help of others involved, if you could have done anything differently to improve the quality of the outcome. Experience benefits only those who take the time to learn from it.
In training and in real missions, fighter pilots meet in debriefing sessions to review what took place. These sessions are led by senior and experienced staff. The central theme is that the only way to develop and learn about something as complex as being a fighter pilot is to review missions, correlate with everyone involved what happened and why, and see if there were any ways to improve the outcome. These discussions often include analysis of strategy and tactics and an exchange of ideas and opinions for alternative ways to deal with the same situation.
The medical community does something similar in what are called M&M or morbidity and mortality sessions (jokingly referred to as D&D, death and doughnuts), though these are typically done only for fatal cases or where something particularly novel or complex was done.
In both cases, it's up to the leaders of the session to avoid making the session a trial ...