Mask tool for cropping

Using the masking option, you have the ability to crop an image to any shape you desire. I'll show the following examples of a rectangle and circle to showcase this option:

As a first step, you'll want to add a shape to your canvas. This should represent the shape for your final image after it has been cropped. So in the example above, I plan on cropping these images into a small rectangle, and into a circle. 

The next step is placing these elements on top of one another. You can see the image needs to be above the other shape as shown here:

Next you will want to select both elements on the layer order on the left hand side. In this case, you can hold the "Shift" key to select multiple elements. From here you can right click and select the "Mask" option:

Now you will have a masked group in the widget layer order. This is more powerful than standard cropping, because you'll still have the ability too:

• Resize the shape widget to be the exact size you want
• Resize or reposition the image to have the exact crop you want