depth of field - How do I get more in focus when aperture is already quite small?

When doing a product shot like this, how do I get more in focus when the aperture is already so small. I don't want to get any smaller for the risk of introducing significant diffraction. Note the lens cap is not exactly in focus (maybe its hard to tell because I have sharpened the image a bit). But I basically center focused the middle of the object at F/14. I was using a 50mm with an APSC camera.