100+ for this.
Custom bokeh is extremely necessary for the overall pleasent visual of Cycles.
Of course, these effects can be obtained more or less by cheating a little the entire system by placing the appropriate textures and objects right in front of the camera. It is even possible to get flares from the sun on the lens. Unfortunately, the times of rendering such a treatment increase significantly. There is a way for everything, but unfortunately this is meh 
The newly released wonderful addon is definitely worth mentioning addon Pro Lens 2
My render test from three days ago with custom textures, glass meshes in front of camera for bokeh and flares. Additionally use Panormaic Fisheye type of camera with long lens (50mm) (sounds absurd).
Raw render without postproduction.
