I do the ambiguous size as well. but like Gorrin said, the only terrain worth putting on the table is REALLY worth noting in the battle. He mentions the sunken road at Antietam and the wall at Fredericksburg etc etc. not every rock wall is a real defense. I made a castle (not pretty) but its also fairly large so I could actually put 2 stands facing each other on the walls, for combat.
though towns are very very pretty I need terrain that helps the game move, not hinder it by making everyone try to find a place for their mini's or forcing warmaster bases to slide all over or fall over onto their sides. the most gorgeous terrain is usually, to me, a game stopper. for now on I am going to try and just stick to putting everything on 1/8" thick plywood from home depot. I get mad at my hills as I cant seem to get the incline right, stands keep sliding off. Stormwind, have you seen the town terrain piece that I made? with the paper buildings? I was trying to make all sorts of crazy rules for it but just found it all to be to technical and confusing so just went back to the basic dense terrain.
As for woods, I shared how I made mine and I still stand by them. mine are not the most beautiful I know but they are extremely functional. I actually remove the tree top canopy and use it as a swamp. a better modeler or someone with more time could make them better for sure.
my terrain is a huge leap from the basic cardboard piece that you had to imagine was a hill or forests from when I first started about 15 years ago with my brother. LOL