I don't remember where I got this nightgown, but I don't like slinky nightgowns. I do love animal prints so I decided to turn this into a slip.
I folded it in half lengthwise and measured from the bottom up each side the length that I wanted the slip to be and the fabric would allow. I placed a pin at each spot. Then I used my ruler and rotary cutter to cut of the top of the nightgown at the pin markings.
I made a casing at the top to fit 1/4 inch elastic.