When you cut out the pieces for a garment, you have choices for the tools you use.  I have 2 scissors and 2 rotary cutters in my toolbox.  When I cut a stabile fabric that will have all raw edges enclosed or finished by serging, I use my straight scissors.  If the fabric will not easily unravel and seams don't need to be finished, then I use my pinking shears.  The same applies to rotary tools.  I often will cut slippery fabric with my rotary tools so I don't have to move the fabric.