You can also ask the XAML debugger to display the layout adorners. While the runtime debugger tool is visible on the application window, click on the third button (as shown in the following screenshot), titled Display layout adorners. It will cause the application window to show horizontal and vertical lines along the bounds of the selected object, so you can see what it aligns to. It also displays rectangles showing the margins:
When enabled, hover over or click any UI element on the application window. You will see the layout adorner for that control, as shown in the following screenshot:
