Hi Fran,
I use Microsoft Publisher but you could just as well use Word for print out. For backups I download the original cover as a high res jpeg, crop it into 3 pieces in a photo editor, then just insert the front, spine, and back into a prepared template that prints out correct full size on A4 to fit the transparent plastic when the edges are trimmed. The photos are simply corner dragged to the correct size to fit the 3 template rectangles. Since the spine is approx half width you just corner drag so the height is correct then drag the outside edge inwards to fit. The vast majority of spine titles are still quite readable, and box set graphics still match and line up in proportion such as the "007 Luger" on the 20 disk special edition spines.
For my own movies I use the same template with a simple 90 degree rotated text box spine, white on black background (more readable at a distance), and stills from the movie as cover or montage with text overlay on front and back.
The final quality virtually exclusively depends on how much you want to pay for the print paper to be indistinguishable from an original.