Along with the 'Smoke' package this is my other go-to resource when creating composites.
A lens flare creates a realistic look and feel in your images with a click of button. Lens flare overlays are just so versatile. I have used them to create a 'hot desert' feeling, to give moonlight a bit more sparkle and even for magic wands and crystal balls. 
Here are 70 high resolution images for you to keep and use in your own artwork.
What will you create? Share your work in the forum!