Some great tips here by some excellent GVers.
Improve your situational awareness.
On the attack, do not drive directly to what you want to attack. The NME is probably waiting for you to do that and you will get shot. Go around one way or the other depending on circumstances. Often if you do this you can even surprise the ambusher(s). Use terrain to mask your movements. Stay on the back side of slopes, hills, trees, even those little bushes. Traveling in a straight line through open terrain is a sure way to have to up a new tank.
Look at where you want to go and what is between you. Identify places where the NME is likely to be hiding like treelines. Scan them on full zoom looking for the NME. I'll even do that while I am moving. Either through the TC/Pintle position or sometimes through the gunsight if distance is very long. If tree cover is sparse, look at the crest of hills for turrets sticking up. Look closely! A good GVer will hide everything but a turret behind a hill.
When you have no choice but to travel on open ground, turn every so often. Make yourself a more difficult and unpredictable target.
Patience, patience, patience