This would be a good idea for a men's shirt refashion. Customize the neck opening after cutting the collar off. Leave the sleeve cuffs on, or cut to length, or whatever length you want, or go sleeveless. Nip in the waist with elastic or darts.
Men's tank, re-purposed with ruffles on the top and an old dress bottom sewn on for the skirt.would be awesome using a Goodwill dress for the bottom. In fact, now that I think of it, any Goodwill dress could become a boho skirt this way!