To clone a project, you must first load the project you wish to clone. With the project loaded, click the Project link at the top right of the screen above your project, and select "Clone".
This will then open the Clone Project window. From here, you can select a template and confirm which project tabs should be cloned, or built from a template.
Note that fields on forms and grids need to be set to "cloneable" in their respective configurators in order to actually clone.