Take a chunk of ground beef, about the size of two golf balls, and roll into a ball. Place the ball on a piece of parchment paper and add another piece of parchment paper over it.
Use your palm to flatten the ball a bit (not too flat, you just want to make sure the top of the ball is flat when you start rolling it out).
Roll the ground beef out to 1/4" thick. Using a knife, cut out a rectangle that is 8" x 5". This actually may change depending on what size you are. In step 5 I talk about how to customize the underwear pattern pieces. The size of the rectangles depend on the size of the pattern pieces. Each pattern piece should fit w/in the rectangle.
You will need 5 of these rectangles for the brief jerky pattern.