As you can see from the grid, It gets REALLY messy quick with the foliage. Also, a hard part about these types of chambers that you need to balance out the level. Too much, the chamber gets to cluttered and looks like Aperture Science is in a rain forest. Too little, it looks like my grandmother planted them. So whats the secret end out doing? Well, I put the heavy foliage on the walls, but making sure its not covering up any check boxes. Then I used the hanging vine models and made it "grow" out of the sides. Also a few metal here and there and damaged tiles helped.
Next comes the lighting. I've looked at a lot of Valve maps and its clear that the light_spot and env_projectedtexture goes hand in hand. They have a very far stretched env_projectedtexture and a far stretched light spot with the outer fading angle to 60, inner fading angle to 1 and really high and the constant set to 100000 or something. Having this set, the map will have a static light, along with a dynamic light to make all those sexy shadows! I've been looking into the foliage moving, but I've yet found how Valve did it yet.
With this map, I wanted to make a pre-GLaDOS awakening, like what if chamber 07 was solvable, and Wheatley did not stop Chell? Also, the fact that if you want the GLaDOS' awakening (Act II) chambers, you need to add panels, some newer walls here and there, and such. And trust me, I've been playing with panels, and its not fun. Takes way to much time and energy to do to be just a special effect. I hope Valve releases those instances in the "next few days".
So what do you have in the end? If done right and playing around, you should get something like this:
Remember, the only two things lighting up that room is a light_spot and a env_projectedtexture, thats it! In the other room, thats where I have my basic light entity.
Before I end this, I would like to say that I'm happy on the lighting system in Portal 2. I always fought with lighting ever since Portal 1, and now to see that you can get an epic lighting with just 2 entities is a dream. The only thing I seem to have issues with is controlling how the dynamic lighting work with certain objects. (ie: Shadow casting on a falling box from a dropper.) I'm sure I can figure it out, or just move away from it.