If you go to the tier one Dark Elf / High Elf RvR (Khaine's Embrace I believe) there is a pretty nice grinding spot.
When you go up the hill (on the Dark Elf side) you'll see a crumbled pillar on the right side of the flag area.
You can easily climb up this pillar and stand near the far edge.
Not completely invincible, but its a nice spot.
Best used with Dark Sorceress (because of range).
Only problem is that when Khaine's Favor is activated, you have to jump down and run.
I've used this a few times and will probably take pics eventually. Too lazy atm, but I hope this helps someone.
If anyone wants to make a guide with pics before I do, feel free