Really, it is easy. Just use a simple formula and they will turn out well.
First select a shape that will be swung or flipped. The shape does need to be symmetrical - if you can fold it down the middle top to bottom and both sides are the same - it will work. Shapes like circles, hearts, diamonds, bracket frames., etc will all work.
In this case I am going to use a shape from the Basic Shapes to make a symmetrical design for the Swing/Flip area. I used the heart shape to make an eight-petaled flower.
Now open the eye on the flower shape. Center the flower vertically over the second (left) set of dashed lines and horizontally with the entire card base. It should look like the image below, more or less.
MTC manual for additional information.)
Exit the node-editing tool bar and select, then split the swing/flip shape. You should see that here are now 4 lines than make up the flower shape, like below.
As I said above, you can use any symmetrical shape for the swing/flip shape. Give it a try and see what you come up with! If you would like the basic card base file (no swing shape), you can download it here.