As I mentioned in my about me, I use Interactive Notebooks (INBs) in my teaching. There are many different ways teachers can use INBs, but the most important thing to keep in mind is that you need to do what you're comfortable with and have time to do. You can go crazy and have a variety of foldables where the students need to use scissors everyday, or you could use traditional notes shrunk down to fit in a notebook. I'm the teacher that has students use scissors everyday. I love the interactive aspect of INBs. I love looking on pinterest, twitter, Teachers Pay Teachers, and other math teacher blogs for inspiration for my foldables. My favorite foldable is one that I made for Trigonometry.
I use the foldable along with SOH CAH TOA, although this is he first time that I have written it out linearly since I learned it in high school. I usually write it out how you see it in below. I think it emphasizes that you divide the triangles leg lengths, where writing it linearly could lead to the misunderstanding of multiplying them.