In Shot Framing
In shot framing can be a very powerful tool in directing attention to the main subject and adding something different to the shot, not all are as obvious as the entrance to Robbers Cave in Oklahoma and you don’t necessarily need the frame on all sides, but it's a very valuable technique to add to your armoury.
In this shot of Crathes Castle in Aberdeenshire, Scotland on a winter day lacking in colour I opted to frame the castle using the tree in the foreground, with the trunk and branches making two sides of the frame, the dark garden wall and shrubbery make the 3rd side and the tree shadow makes the 4th, effectively guiding the viewer toward the castle.
The gallery below shows more examples of in shot framing and the benefits it can bring to an image, some also show how you can force the frame by moving your own position to create it rather than just waiting for it to occur.