You won't be able to make cropped flared jeans at home or on your own until you have a solid understanding of sewing and measurement. If you have flared jeans, you can simply measure and cut them to the ankle while keeping the frays. You could also get a regular-fit flared jeans and then cut them, but both would cost about the same, so you might as well get the cropped one. Unless you already own a pair of flared jeans (in which case you can cut and sew a cropped version), you can get one for yourself.