1 - Double-click the Pick tool to select all objects in a project, or press Ctrl + A. Select one or more objects, and holding down Shift, double-click the Rectangle tool to create a rectangle around the selected objects.

2 - To select an object hidden from view, hold down Alt and using the Pick tool, click the topmost object one or more times until a selection box appears where the hidden object is located.

3 - To marquee select one or more objects, you don't need to drag around the entire objects. Just hold down Alt, and use the Pick tool to drag a marquee that surrounds parts of the objects.

4 - To select an individual object inside a group, hold down Ctrl, and click the object.

Tips provided by Ariel Garaza Díaz, CorelDRAW  Master and Graphic designer.