I think it was my photo you saw in flickr and I can tell you how I do it but that’s necessarily the “right” way. 🙂
I use 2″ elastic because the ribbing I use just isn’t strong enough. The length of elastic I use is her waist measurement minus 1″. I overlap it and sew it together to form a circle. For the ribbing I use the same length as the elastic and 5″ wide and sew the short ends together to form a circle. Then I fold it in half with the right sides together and put the elastic inside it. The waistband is now 2 1/2″ high, 2″ for the elastic and 1/2″ seam allowance. I zigzag the bottom edges of the ribbing to keep everything together and the elastic from falling out. Then I stretch it to fit the waist of the pants and sew it right sides together (although either side of the ribbing band is fine). Here you can either find and mark the quarters of the waistband and the pants and match them to evenly distribute the stretching or I stretch a little in the front and then do most of the stretching in the back so the front of the pants look flat. Then I press the seam down and topstitch from the right side to keep the seam allowance down.
I hope that made sense, just ask if you have any questions. I’m sure if you goggled it you would find a good explanation too. Good luck!
