Even if you've lost your shirt at the casinos, it's still nice to tip your wait-staff and room service people well! They work hard for their money!
Be sure to start with Part 1 of the Shirt Instructions
Fold the rectangle right to left again, bringing the edge right underneath the collar. Looks pretty cool, eh?
OK now unfold the rectangle back to the start. Lay out that left third flat - don't worry about actually flattening down the entire piece, though. This is just a preparation for making the sleeves.
Here is the part I always hated in origami books. They did this really nasty move and then just said "voila you have sleeves!" :) Here is the trick. Look at the next photo. You know you want sleeves to appear to the right and left. You already have the fold in place, where the edge of the "shirt" will be. Focus just on what will be the left hand sleeve when this thing folds back up together again. Hold the top fold on that edge gently between your thumb and first finger. I marked the spot with a green dot. Now hold the bottom fold on that same edge, with your other hand. Where you are holding will be just about the "undearm" of the shirt, i.e. the bottom side of where the sleeve meets the shirt.
Now slowly "stuff" that extra shirt material back in between the shirt outer layer and the sleeve inner layer. If you hold the origami as shown and look at the picture below, it will start to make sense. This is DEFINITELY a 3D operation, not a flat one. Push in with both sets of fingers at the fold space, to move that fold inside the origami shape.
Once you get that part done, you are set! Fold the right back over to the left, and tuck it under the collar again!
