Throughout my graduate school experience, I have come across multiple student development theories, and have even completed a full course that focused solely on the different theories that pertained to working in the Student Affairs field. 

The theory that has been the most applicable to my advising experiences and helpful to me is Baxter-Magolda's theory of self-authorship. When students start reflecting on their experiences, and asking themselves why they are making the decisions they are, it tends to help them see the full picture better.