Photography is not all about sharp images. Move in close with an f/2.8 aperture and things go blurry fast. Pull out the "artistic" keyword to clarify the blurriness, and those viewing the picture will relax about the lack of sharpness.
When shooting for a blur effect, consider the colors and contrast and how they interact in the frame.
When this eastern tiger swallowtail turned his back side to the camera, focusing on the back edge of the wings creating an "artistic" blur.