If you haven't already, cut 9 strips from T-shirt 1. Each strip should be 3 inches. Repeat with another shirt of contrasting color, so that you have a total of 18 strips.
When done cutting the strips, sew the right sides together. Repeat until all strips are sewn. When done, iron open your seams for a flat, crisp look.
Next, measure your waist with the elastic to get the right length and then cut and pin it to the top of the skirt fabric. Stitch two lines on the elastic to connect.
Fold the skirt fabric in half with the right sides together, and then stitch the two ends together. Use two seams to ensure that stitch is secure. Once you are done with that, hem the bottom and iron out all your seams.
For the dress's bodice, place a pin on your shirt where you would like the skirt to attach, and then cut any excess from the tank's bottom.
Pin the shirt and skirt together, and then sew 2 seams to firmly attach.
And that my friends, is how you make this striped dress. Not too hard, right? You can see how I placed the seam down the side and tried to line up all the stripes. You have to be aware of that when you are stitching down the sides.