Magnus...you couldn't have said it any better. The key in Woods games is the use of the terrian and vegetation. And the second most important is what Reckless said...bring a buddy. Even you "sniper" types. Spotters are great. You can put your buddy in a more exposed position, to capture the attention of your opponents. While they're busy with him, you can get yourself into a position to fire from a concealed position, and pick them off one by one.
Run the rope. On my field, the one boundary is alongside a dirt road. There's a large line of brush about 5 feet into the field...and grass in between the two. For some reason, very few opponents guard that flank. I've snuck up that boundary several times, and come in behind the opposition to take them out.
(Of course, one time, two of my team members didn't know I was doing that, and they came in behind ME, and shot me in the back of my head. Dummies didn't check my armband first before they shot. Trigger happy "Shoot first, ask questions later" types. Bah.)
Anyway, make use of thorn bushes too. Just be sure to wear thick clothing if you don't want to get scratched up! Someone said it, but take the most uncomfortable route...it's less likely to be guarded, and you can attack from an unexpected direction, quickly giving you the element of surprise.
"If you don't stand for something, you'll fall for anything."