This folding technique produces a curved shape resembling a nun's or nurse's cap. It is a general-purpose shape that works well boiled, steamed, in soup, or deep-fried.
For all wonton folds you start by placing the square of wonton skin on a flat surface (such as a small dish) and putting a round 1/2 teaspoon dollop of filling in the center, in this case perhaps a bit nearer the A-C line than the E-F line:
Now moisten your index finger with cold water and trace a streak above the filling, along the arc G-H-I in the diagram.
For the nun's cap shape, fold line A-B over so that it is directly on top of E-F:
Press firmly around the top of the filling (around the moistened arc you made before folding) to seal in the filling, eliminating as much air as possible. For the second fold, you want to fold edge A-B directly over edge C-D, along the red line in the diagram. You will end up with this shape:
Now fold back the top (the double) layer of wrapper at point A, and moisten its underside at point C. For the third fold, you want to bring the top (double) layer around so that the top layer from point B overlaps on top of the top layer from point A. Press so that the moist bit at C seals points A and B together to prevent them from coming apart during cooking. The nun's/nurse's cap shape should now be apparent.
Your wonton is now ready for cooking. Placing the finished wontons under a moist towel helps keep them from drying out as you fold them.
-Paul W.