A different twist on using selective focus to emphasize your subject. Try putting a distant object in focus with a much closer object out of focus to frame the subject. The key is to make sure there is a separation from the near to the far subject.
Depth of field is a function of focal length, distance, and aperture. By using a long focal length, a wide aperture, with objects separated by a large distance, you can create this effect.
Depth of field of my 600 mm lens at an aperture of f\4 focused at infinity is from about 2000 ft to infinity. So everying closer than that will be burred. The maple tree in the foreground was about 50 feet away so by carefully positing the camera I was able to create this nice framing effect suggesting the moon in the fall.