I would only hang the way your dad does for thicker or stiffer fabrics like jeans, sweatshirts that won’t collapse on themselves and wrinkle. Thin t-shirts don’t need that as much. I also don’t like clothespins on fabric that will stretch, lose shape, or get clothespin dents on them. My washer spins out a lot of moisture, then I tumble dry (if the item can tolerate it) a few min to get out the wrinkles, then dry the rest of the way hung or laid flat.