If you've ever worked in a clothing store, you know how much folding, refolding, hanging and rehanging is involved. When you are not selling the clothes, you are folding and hanging them. This uninteresting and repetitive work is, for some, habit-forming. Perhaps you still fold and hang your own clothes the way you were paid to years ago. After all, you got pretty good at it. Those who work at the Gap are known for their fast and initially puzzling way of folding t-shirts. Though you may have never worked there, you can learn how to fold your own t-shirts this way. (And you'll be one step ahead of other potential Gap employees should you apply.)
Lay the t-shirt flat with the front of the t-shirt facing up. The side of the t-shirt should be facing you, meaning that the shirt's collar should be to your right and the bottom of the t-shirt should be to your left.
Put your left index finger in the middle of the t-shirt and "draw" a line toward you until you get about 1 ½ inches from the side of the shirt. Pinch both sides of the fabric at this point with your left hand.
Keeping the first pinch secure, use your right hand to draw another imaginary line from the first pinch up the t-shirt to the seam on the shoulder. Pinch the front and back fabric here with your right hand. Now both hands are pinching the t-shirt.
Bring your right hand down past your left hand to the bottom of the t-shirt directly under your left hand. Your arms will be crossed. (Again, imagine a line going from your left -- pinched -- hand to the bottom of the t-shirt.) Pinch this fabric with the right hand so that your are now pinching four layers of t-shirt with that hand: the front and back of the shoulder seam and the front and back of the bottom.
Make sure the t-shirt looks like a mess of fabric at this point. That means you're doing it the right way.
Holding firmly to all pinches, lift the t-shirt from the flat surface while uncrossing your arms.
Shake the t-shirt until it hangs from your hands smoothly. It should no longer look like a mess of fabric.
Lower the t-shirt back onto the flat surface sleeve-first so that the front of the sleeve that's hanging touches the surface, creating a horizontal fold symmetrical to the one created by your pinches.
Now, lay the t-shirt down towards you (with the front facing up), and you're done.