My project on rendering feasible flags for real use is progressing towards something more realistic.
Also, simple pinning is not giving a nice result (I had a former poor version created). But as I tried cloth interaction (to go for ropes and flags) this was much to complicated for Blender to handle. So I tried a fake with a pin and a graphical version of a ribbon. The material is now a mix of glossy, translucent and transparent shaders allowing the flag just slightly have environment lighting and objects behind shine through. In my mind this is not ideal, because the ropes are heavily stretched and they also have no thickness.
I would be very interested in knowing who overcomes this with a neat idea. Maybe you can apply a different cloth material to the parts you design to be the rope. Still it is pretty much 2D and does look a bit weird.
The fact that I added a second flag multiplied my issues. I had problems with the physics simulation. Despite clearing the cache properly, as soon as I duplicated one proper simulated flag, the copy behaved totally weird. I posted an enquiry on blenderartists.org, but got no solution. I finally resolved it by using only one cloth simulation with two clothes in one object. So the two flags actually are the same mesh, textured across a seamless UV map. This worked fine, although I faced some limitations. Maybe this was resolved in a later version of Blender (the issue was with a 2.6x version).
Last I added compositing with some chromatic abberation, and fog glow and of course vector blur for the movement. I tried less samples in Cycles for a grain effect and as I use an HDR environment already giving a right side vignetting, so I did not add an artificial one.
The logos of BT and KPN are copyright of the companies respectively. This is an actual partner illustration we used commercially.
I will create a new version with non-commercial images and post a tutorial on my youtube channel soon (this is one of the first I feel bold enough to go public on). If you are interested in the blend-file, contact me.