Ok this is a simple terrain exploit of simply dropping down onto a notch and being able to keep anyone off the flag (if you're ranged) yet having low risk of being spotted. I'll get the screenshot up in a little bit I just wanted to make sure I had this posted.

Basically you go over to a certain part of the edge, tab walk, and slip off onto a discreet ledge, you still have range of the flag plus about 15 feet. My suggestion for spells if you're going to be down there are spells that don't leave a trail (shadow bolt, fireball, etc) because the enemy will be able to see where they are coming from. On my mage I use untraceable spells such as scorch and if there happen to be a lot on the flag I use either blizzard or flamestrike.

Here are the Screenshots
http://i97.photobucket.com/albums/l2...106_211059.jpg
http://i97.photobucket.com/albums/l2...106_211200.jpg
Hope this helps.