While you might not be able to add a Bokeh effect to your photos, you can certainly use any photos (even the bad ones) and create fantastic background papers. This process is very easy, but a bit tedious.
Download the PDF document that suits you best:
either the Detailed handout with every basic steps,
or the Summary, which covers only the main points
(assuming you are already familiar with the basic steps)
If you find that this effect is just a bit too tedious to achieve, you can take a shortcut and get this script. It will do the same thing, just faster.