I really enjoy chamfering and playing with chamfers as a design element.
Here's an acrylic on paper, recently framed, by mid-century Texan Edward Carpenter Bearden (1919-1980). We had fun coming up with this adaptation of our Aurora frame with flat mortise-and-tenon corners. We often use it with a chamfer all around the sight edge. In this case we played off the mountain peaks in the picture by adding the sets of points near the corners. On the same theme, Trevor shaped the corner plugs with a peak rather than our usual pillow form.
The frame profile is 1-1/2" wide, and the wood is black walnut greyed down with a black wash.
Might have framed this piece close, but the customer preferred to mat it, in part to scale up a fairly small painting (about 11" x 17") to make it a stronger element on the wall—a perfectly good reason. The grey mat avoids the separating effect of white matting.
Another entry on chamfering is here.