Editing Warhammer 40,000/Tactics/Kill Team(8E) Guide and FAQ (section)

==How much terrain do I need?==
Look at the GW kill zones, in particular mechanicus and fronteris. They come with about 50% of the terrain needed. If you look at the GW tournament packet, they have every player bringing a painted kill zone (or equivalent amount of terrain) and you combine it with your opponent’s collection to fill the board. 

===How much of my terrain should be LoS blocking?===
You don’t need a huge amount to make the game function, especially because being partially covered actually does something in KT, but it’s balanced around a fair amount. If you setup one of the five or six objective games and there are lots of places where you can see more than two objectives then that’s not enough. If you can see four or five objectives from multiple locations then that’s definitely not enough.
If the Tau player is complaining that’s probably about the right amount of LoS blocking.

DON'T PUT ALL OF YOUR LARGEST PIECES of LoS BLOCKING TERRAIN IN THE CORNERS! Why the fuck do so many people do this? If you have an opponent that insists on doing this then get some random person to arrange the terrain or stop playing games against the resident asshole. If you do it then stop being the resident asshole.