How do I unshrink my beautiful new viscose/rayon dress?

omg the same thing happen to me today when i washed my cropped tee made of the same fabric my tee that once was stopped right above my belly now shrunk to the middle of my belly lol i ironed it and loosen up a little but the best thing to do is re wash in warm water and let it hang dry, after iron it inside out and it should be fine