Step 1: What you'll need
Step 2: Cutting the shirt
Draw a line straight across the top, just under the neck. Cut through both layers.
Cut about 1 1/2" off the bottom. Shirts can vary, so alter this to meet your needs. You'll be adding about 3" back on later.
Step 3: Cutting the second fabric
Cut two pieces, each 1/2" longer than your shirt is wide (for my shirt it was 18") and 3 1/2" wide.
Step 4: Making the braid straps
Braid together, keeping the wrong side turned in, if you have one. Pin the finishing end with a safety pin so it doesn't come unbraided.
Step 5: Armholes and neck
Turn the upper edge at the neck under 1 1/4", then turn the raw edge in 1/4". Stitch with a narrow zigzag to form a casing. Make sure to stitch all the way to the armhole instead of stopping at the edge of the casing inside.
Step 6: Adding the braid to the shirt
Sew the ends of the braid together. Pull until the sewn-together end is inside the back casing.
Adjust braid so it's equal on both sides. Pin in the center of the casing. Gather the shirt equally on both sides of pin by pushing toward the center while holding the braid. Stitch the edges of the shirt to hold the braid in place. Repeat on the back, gathering less.
Step 7: Finishing the bottom edge
Pin the loop to the bottom edge of the shirt, right sides together and edges even. Stitch with a 3/8" seam.
Press the seam up toward the shirt. Zigzag stitch over the raw edge on the inside.
Hem the bottom with a 1/4" seam.
Press the seams and you're done!