I use a similar method to byroncallas I think. My usual steps are as follows:
1 - create a new layer over the layer I plan to cut a section from.
2 - set the new layer to use the "Cell" preset
3 - use the crayon or chalk tool to color over the area I wish to cut out of the layer beneath it (creating a sort of mask).
4 - one I have masked off the area I want to keep, I make a stencil from that layer and invert the stencil once I have created it.
5 - duplicate the layer I plan to cut from.
6 - erase away the area around the stencil.
For a visual of this, I have made video you can download from the follow website: http://www.mediafire.com/file/wzjqe1...utandpaste.wmv
Just click on the "Click here to start download..." link once you're there.
Nothing is easy to the unwilling.