Using both hands, pinch the shirt on the side opposite you at two points: (a) with one hand at the shoulder, midway between the sleeve and the neck and (b) with the other, halfway down the shirt.
While holding the two points, cross your left hand over your right, bringing the shoulder down to meet the shirt's bottom hem, and grab the hem.
Lift the shirt so it hangs in front of you. Uncross your arms without letting go of the shirt, and pull the fold taut as you do so.
Place the hanging sleeve on the work surface, and neatly drape the folded portion over to finish.