sorry guyz, for the building, I'll need a little more time with it :-)
Mad Aussie: Yup, I only used terragen, wilbur, and wrp editor to build my terrain..... "BUT" I also made terrain objects with the oxygen. The key is new model.
If you make more detailed terrain models and place it in wrp editor, it will give the game a different taste. That is what I basically did. The reason why my Afghan map looks a little like Ghost Recon Desert Siege is because of the new terrain model. A lot of observations, research, looking at pictures and some little experience in oxygen will pretty much change how you'll think about the OFP terrain.
There's a lot more possibilities in OFP so it's just about Ideas.... Imaginations...
Observe the nature, other CQB games and think of what gives these games the reality, the suspension, and so on.
I hope this tip inspired you.