Your preferred Lens, Reticles, and Reticle Colours conbinations. Also a place to discuss which combinations work well in certain situations.
I've either avoided the Red Dot/Reflex or used the standard Red Dot in my first months of playing. Recently, I stumbled upon a thread much like this blog, where people were discussing sight customization. Apparently an orange lens and blue sight work well in the dark. I use a clear lens and green hollow circle. A person on the thread said that the eye is naturally attracted to the colours green, red and white, and can focus well on a circle. So I did a green circle. It makes quite an improvement on my game.