How do you start working on a personal project? Talking about what kind of software methodologies you use, what steps do you take first and what tools you use.

I am still a colege student and while I have studied about software methodologies, I didn't really use them in any way until recently when I joined an internship and worked in a team with professional software developers. I want to do my personal projects in a more structured way as well like I did on the internship but I am not sure how to.