Anne, there are many designs that could be used. I guess the easiest would be a nine patch or 4 patch. I would watch some of the Jenny Doan tutorials on you tube. She starts with precuts, like 10 inch squares or 5 inch squares. You could cut those out of the shirts. I could get at least 8, 10 inch squares, out of my DH's, not counting the sleeves. He is a big guy! I would make another quilt for yourself. It would be like a hug from him. My DH likes to wear the tropical print shirts in the summer. I have about 3 stashed away already, the collars get worn and then they are mine.
If you haven't watched the tutorials, you will enjoy them. Jenny makes it all so easy. She is a very nice person and has done amazing things for her little town. I just wish I lived closer that 6 hours away.
Good luck with your project and here is a hug from me too.