You will need:
T-Shirt that fits you well
T-Shirt to use for scraps (or shirt scraps)
Cut the neck out of the T-Shirt, then flip it over so the back of the T-Shirt is facing up.
Find the center of the back of the T-Shirt ( I usually just fold the T-Shirt in half width wise to find the center). Then measure 2 inches down from the neckline. Mark this spot with chalk or pencil.
From center mark you just made, measure 4 inches out to the right. Repeat on the left side of the mark. When you have made both marks, connect them to make a horizontal line.
From the first center mark, measure down 5 inches and mark with chalk.
From this center mark measure out 4 inches to the right and mark with chalk. Repeat on the left side of the center mark. When you've made both marks, connect them to make a horizontal line. You should now have two horizontal lines parallel to each other marked on the T-Shirt.
With scissors, carefully cut the horizontal lines you've marked. Make sure you don't clip the front of the shirt when you're cutting. You'll now have two horizontal slits in the T-Shirt.
Grab the scrap shirt and cut the bottom hem off.
Now cut an inch wide strip from the bottom of the shirt.
Cut both ends of the strip so that you'll now have two long strips of fabric.
Cut one of the long strips of fabric in half. Now you should have two short strips of fabric and one long strip of fabric.
Gently tug on each strip of fabric so that it turns in on itself.
Now measure out a 3 inch by 3 inch square on the scrap T-Shirt. Cut. You should now have two 3 inch by 3 inch squares of fabric.
With your T-Shirt inside out, slip the long strip of fabric through the horizontal slits (centering it) and tie in a double knot. Trim the long ends from the strip.
Now with your shirt right side out, find the center of the top of one sleeve. Make a mark at 1/2 inch and 1 inch.
Clip two small holes where you've marked on the sleeve. Repeat step 14 and 15 on the other sleeve.
Slip one of the small strips through the holes as pictured above.
Slip one 3 inch by 3 inch square of fabric through the tie (centering it) and tie in a double knot (knot will be on the inside of the sleeve). Repeat steps 16 and 17 on the other sleeve.
And you're done! Now you've got a cute Bow Tee and you didn't even have to touch a sewing machine.