What ya need: A Tee that's at least one size bigger at the waist then your normal size or a Loose Fit in your own size like the one I used from the Zara. Some scissors, glue or sewing tools.
Turn the Tee inside out
Cut the sides open
Twirl the fabric two times
(can be one time but the wrong side of the tee will turn to the front so keep that in mind)
Hand sew/ Glue or seam the sides together
(make sure that the beginning is securely fastened together and the sides have the same length)
Side mark: Your Tee will become extremely tight-ass at the waist so if you would like a wider version of the Twist & Twirl Tee you should try a fit that's wider from the waist down. Also some extra stretch will help!