You give it a light spray before you make the cut, and give it 5 minutes or so to slightly lose its tackiness a bit (so it doesn't grip your scissors as much). Make sure you spray the back side of the fabric, not the side that is going to be visible.
For extra stability, you can tack together two layers of fabric. This will let you handle and cut the fabric almost like a pre-preg, but you will lose the drape and flexibility of the dry fabric.