With the cutter, you still need to prep fabric to fit the die.
I never fit the die with fabric, only the die shapes. I measure the width and length of the shape and cut my fabric to be 1/2" bigger. I write with silver sharpie the size of fabric I need on the die foam. Saves me a lot of time. For BOB dies when all the shapes are on the die I fit the fabric to cover the shapes usually in a square or rectangle. I do heavily starch my fabric before cutting to stop any distortion due to stretching especially when cutting six layers at a time.