You'll need the following:
an apple, a knife, a pen, and a piece of aluminum
Using the knife, core out the apple making sure that you do not puncture the bottom of the apple.
Stick the shaft of the pen into the side of your apple pipe. (This will act as the mouthpiece of your pipe.) Remove any apple that became trapped inside the pen. Take a piece of foil and poke a few small holes in the middle. Stick your foil screen into the apple pipe. Enjoy the "fruits" of your labor and spark it up. You can always eat the apple after you're done.
an apple, a knife, a pen, and a piece of aluminum
Using the knife, core out the apple making sure that you do not puncture the bottom of the apple.
Stick the shaft of the pen into the side of your apple pipe. (This will act as the mouthpiece of your pipe.) Remove any apple that became trapped inside the pen. Take a piece of foil and poke a few small holes in the middle. Stick your foil screen into the apple pipe. Enjoy the "fruits" of your labor and spark it up. You can always eat the apple after you're done. 
