1) Tear a piece of scrap paper and lay it on your project.

2) Apply
ink to the uncovered portion of your project using a sponge or brayer.
Make sure to overlap the ink onto the scrap paper.
3) Add stamped images as desired.

4) Lift the scrap paper to reveal your faux torn edge.

This is a great technique for creating an organic horizon line (mountains, hills, etc.).