What are some good MCIs to take once you’ve been promoted to Corporal?

Spelling and math for Marines!!

Just so everyone in the future is aware I asked this question when I was a Corporal.

I believe you should take personal finance. Leadership Courses, and the ones related to your MOS

Join a Toaatmasters club too. It will look good for promotion purposes. View it as a supplemental benefit.

Most of the courses I took were ones that helped me in my MOS. Although that was 30 years ago and SO much as changed I also tried to branch off into courses that helped me be more productive and valuable to my unit as well as helped me towards my degree. (MBA)

Fundamentals of marine Corp leadership.