We would recommend using a small piece (about an inch) of Stable tape at each end of the template to provide a resistance to slip. We use either a Supreme Slider or Sew Slip and yes you do need an extension table if you are going to free motion quilt with templates. There are many videos showing the method on You Tube Google search "Westalee Youtube".
Sew Steady are our US manufacture and Distributor based in Oregon