4) Measure waist and divide by 2. Cut the waist of your pants as close to the crew neck, marking waist length + seam allowance (see illustration). I use a ruler to get a straight line from the top of the front crotch to the back crotch. One half of your waist measurement (+ seam allowance) should tell you where to start the back crotch slope cut. I cut this from the top, using a straight angle, and curving to meet the original cut line.
5) Baste you pattern t-shirt together before cutting you sample garment. With right sides together, sew front and back crotch seams. Then fold front and back crotches right sides together and stitch the length of both leg’s inseams. Try on inside out, so you can pin the adjustments you want to make to the pattern.
For your final garment, cut a piece of elastic for the waistband that is smaller than the waist of the garment (and comfortable around your waist), and zigzag raw edges together into a circle. Mark or pin the elastic in half, then again to get 4 equal quarters. Match your front and back crotch seams to determine pant side seams, and pin. Matching crotch and side seams with elastic points or pins, fold raw waistband over elastic, stretching elastic, and zig zag in place. Hem bottom of pants, or leave raw. Enjoy!