First of all draw a swan template on plain paper and cut it out. Take this cut out template and put it on the back of the baking foil and draw around it to copy the shape. (for making identical other wing, just flip the one you've got). I draw the shape on the back of the baking foil as I don't want the pastry to absorb any colour. As the baking foil is see through it's very easy to see the shape from the other side.