Adding a lens flare can make or break a certain image. The best kind of lens flare is the natural one taken through the actual lens of a camera, but if we do it the right way, we can recreate it using Photoshop just as good.
Remember the legendary Predator movie with Arnold Schwarzenegger? Those Predator aliens had this thermal view feature so they could their prey even in complete darkness, let's Photoshop it.
In Photoshop CS6, the new version of Photoshop, you can use special cropping tool and you are done, but that doesn't mean you cannot achieve the same result with older versions.