I think it is all about turning things inside out…
if your shirt is inside out, you put your hand in you grab the end of the shirt and you pull your hand out, once it is like that if you shake it all around then… the sleeves (if short) will get fixed too… if the sleeves are long then you may have to do all the put your hand in and hand out and shaking all around all over again… this time in the sleeves.
It works for socks and pants as well….
Elemental my dear Watsons….