Putting together a costume design portfolio for college visits?

I will be entering college in a year and am planning to study technical theater, specifically costume design. Many of the colleges I will be applying to have theater scholarships for both actors and techies, but they require an interview and a portfolio. I have a general idea of what to put into my portfolio - sketches, pictures, swatches of fabrics- and I have a lot of stuff that I could include, but I just don't know HOW to put it together. For example, what kind of binder or notebook should I buy? Should I glue the pictures to cardstock, or is there a better way to attach things that would let me update easily? Should I include lots of in-progress pictures or just the finished products? If I didn't sketch the costume before I made it, what do I do? How long should it be? Should I include blurbs about the design inspiration? Is it all right if I didn't take the photos myself? I have a ton of questions and any help is greatly appreciated. Thank you!