Thanks, TangoCharlie! It's very simple and a nice project for sewing beginners. Measure the desired length and width of your waistband (doubled) and add seam allowances. Cut fabric for waistband from t-shirt (directly under neckline, everything below will be turned into the skirts bottom. You should have two rectangles now). Sew sides of waistband and fold in half. Press. For the bottom you can retain the side seams and hem of the t-shirt. Just gather the top and sew to the raw edges of the waistband, right sides facing (put the waistband inside the skirt). Does this make sense? I recommend the Craftsy Course "Sewing with Knits". Great basic patterns and techniques!