Download this set of 3 Photoshop actions and 2 light leaks courtesy of SparkleStock.
This kit lets you simulate retro films from AgfaPhoto and includes some flare/lightleaks as a finishing touch. For even more, you can upgrade to the pro version which includes a lot more such as an authentic-looking date imprint. These Photoshop actions are compatible with Photoshop CS3+ and Photoshop Elements 11+.
Retro Photo Kit
Using the Photoshop actions, you can simulate one of the three AgfaPhoto films with just one click. The light leaks are transparent PNG files that you can place over your image. To blend them with your photo, the blending mode to Linear Dodge or play around with the other blending modes.
Retro Photo Kit also comes as a pro version which includes way more film emulations and light leaks. It also has a Photoshop action and font that lets you add an authentic-looking date imprint on your photo.