Post-Processing : Lens Flares
Lens flares are common post-processes that were rendered popular by the infamous "Lens Flare" filter in Photoshop which can be easily recognized.
Lens flares are created by light entering through a camera objective and reflecting multiple times off the surface of the numerous lenses inside it, creating several recognizable artifacts.
I won't linger on the optical details of what creates which lens-flare artifact, I'm only concentrating on their visual aspect. For that purpose, I relied on a well known After Effects plug-in called "Optical Flares" by Video Copilot (http://www.videocopilot.net/products/opticalflares/).