This is just a short tutorial that's good for interesting borders.
Step One
First, you need to open the document you're going to use the effect on. I chose this image of a road.
Step Two
Now, take your lasso tool. Set the feathering to around 5 px, and start drawing a little outline around your image.
Step Three
Go to selection>invert. Ctrl + c (copy) it, and paste on a new layer.
Step Three
Now, we're ready to do the actual effect! Go to filter>sketch>waterpaper. You can mess around with the settings, but the defaults look good, too. Default: 15, 60, 60. Used: 15, 60, 75. Optional:
You can change the opacity of the layer with the effected edges on it if you want to be able to see parts of the edges =D