Start out with two or three different kinds of fabric. For this shirt I just used two so I could have a side of the sash blend in with the top. I used contrasting colors on my dress, pictured at the end, and I thought that turned out really well.
Measurements needed for this shirt/dress:
Measure from the point you would like your shirt to begin down to the length you would like it to be. Include the measurements for your elastic casing and your hem.
Next, Measure around the thickest part of your body. An ex. If you are making a shirt, it will probably be your chest. If you are making a dress or tunic it might be you hips. Divide that in half to get the width of your shirt panels. Then add seam allowance*. I added one inch to my measurements. I like my shirts to have a little give to them.
Sash measurements, Take the width of your shirt and divide it by two. Then add however long you want your sash to be. If you are going to be tying the sash into a bow I would make the sash a little longer.
*I will probably never designate a seam allowance for my tutorials because I know a lot of women like to finish their seams a different way or they are more comfortable working with a larger seam allowance. Whatever floats your boat.
Create your elastic casing on the top of the shirt Fold it over twice to have a nice finished edge.Remember to leave an opening so you can slip the elastic in. Take your elastic and wrap it around your chest, right where you wanted your shirt to start. Make sure it is tight but you still need to be comfortable. Mark where to cut the elastic. Then, attach a safety pin to the end of the elastic and pull the elastic through the casing. Try the shirt on and make sure you are comfortable. Then sew up the opening you left for the elastic and hem the bottom of your shirt. You're finished!!!