Ive seen people get a similar effect by placing individual napkins one by one on top of each other placing them at a slight angle to the last. However this takes up precious time when you could be using it to chat to your guests.
HERE IS THE SIMPLE CHEFS WAY
Step1. Select the amount of napkins you wish to use and stack neatly, just as they came out of the packet.
Step 2. Place your finger tips and thumb onto the center of the top napkin ( your hand shape should be like a spider or like your picking up a lemon )
Step 3. While gently pressing into the napkins twist your hand clockwise at far as you can keeping a little pressure on the napkins. You may need to repeat the proses a 3 or 4 times.
Step 4. Depending on how you want the spiral shape to look keep going with step 3 and add more pressure to the napkins which will turn the napkins lower in the pile.
Simple, just add a napkin Lily or two on top for the final touch.