Lay your serviette square out flat before you in a square shape.
Fold the bottom left and right corners to meet the top left and right corners. You will now have a rectangle with the crease along the bottom edge.
Place your finger at the center of the top edge, with your other hand fold the bottom right hand corner to meet your finger.
Now take the very top right hand corner, and fold it to the very top left hand corner. You should now have a square shape with a diagonal line running from top left to bottom right.
Take the bottom left hand corner and fold it up to the top right and corner.You will now have a right-angle triangle (the right-angle being in the top right hand corner).
Pick up the serviette so that the right-angle is facing away from you in the North position. Carefully open the inside folds so that you have something that resembles an ice cream cone (but with one side of the top higher than the other)The side closest to you will have all 4 loose corners visible.
The side with the right-angle triangle will be the lowest point of the cone shape. Grasp this place ( it's also where the join is) firmly and carefully turn it it a little inside out, so that a small cuff is made all the way around. The bottom of your ice cream cone is now an elegant cone shaped sail and the cuff rises at one end like a little boat.