I have built my first few scripts with a nice little GUI on them, as the tutorials have shown me, but none of them address what to do for a more complex program. 

If you have something with a 'start menu', for your opening screen, and upon user selection you move to a different section of the program and redraw the screen appropriately, what is the elegant way of doing this? 

Does one just `.destroy()` the 'start menu' frame and then create a new one filled with the widgets for another part? And reverse this process when they press the back button?