For this tutorial I'll be using this Lindsay picture:


Now get the freehand selection tool.


Draw whatever you want your desired border to be. Make sure your feather is 0 or 1 and smoothing is 1 like shown:


Now just go ahead and cut out the part of the picture you want like so:


After you meet the last 2 ends together, double click and the border should be moving.


Now, press CTRL X. It should be gone.
After that, make a new document 600x600, make the filling color black.


After that, press CTRL E and click, then your picture should be on the plane.


Now go to selections>modify>expand.


Put the number of pixels as whatever you want. Then Press CTRL C, CTRL V. And there is your new bordered image.