|Before starting to sew you need to get the waist measurement of the recipient. After obtaining this you need to cut your elastic 5-7 cm smaller than the waist measurement. Sew the elastic together. After doing this follow these steps: Step 1 & 2, Step 3, Step 4 & 5, and Step 6.
I find this way of doing elastic much easier. You don't have to worry about the elastic becoming twisted inside the casing and you can sew the elastic on while making the casing.