I always play with unit 3 size and 2D terrain so the enemy can't hide behind trees, I mean in war you have to be able to see him to kill him, seems logical to me..
I therefore regard the SHIFT-T key as the useful 'Agent Orange' deforestation tool..
When composing screenshots I approach the subject like a film director, using whichever unit size, zoom setting, camera angles and terrain density creates the most dramatic visual effect, also using an image program to make sure the scenes are properly lit and so on..
As you see from my astounding AAR's, I use two pictures per masterpiece, the first being a high-level birds-eye view of the whole battlefield with size 4 units and 2D terrain on which I paint breathtaking arrows and symbols etc, then for the second pic I zoom to low-level so my spellbound audience are taken into the very heart of the battlefield like on an exciting virtual ride at Disneyworld.
"That we may wander o'er this bloody field
To book our dead, and then to bury them,
To sort our nobles from our common men" - Henry V