I am a huge fan of Army surplus clothing. It is practical (obviously), made to last, easy to clean and like denim is made from strong fabrics that allow huge scope for dying, recycling, bleaching and easy to sew.
I also love high waisted jeans, I make them super snug and high waisted for myself. It is easy to show the waist with a crop top but I'm afraid my confidence isn't quite at the exposed crop top stage so I found a military shirt in Brooklyn New York recently that been shortened and I think its such a great idea! It can worn over a body, t-shirt as a cropped shirt or as a loose jacket.
Shortening a shirt can be done by hand or by sewing machine and as always can be alternated at home or a local tailors or even dry cleaners. I love the idea of using the shortened shirt and wearing it as a 50's style drop jacket - even rolling the sleeves up or cutting them into a 3/4 length.