Do your regular job with Spirit Farmer just outside Port Sledge. Like always better drop in normal mode.
Mind that Grawl Crones have Chilblains that will take down regular enchantments. Also, signets are not spells and can go through skills like Shadow Form and Obsidian Flesh.
Team up with a friend, one runs any/Rt with Vengeful Was Khanhei and some tanking skills (anti-KD specifically), your friend runs /R with some running skills, EoE and QZ. Start from Port Sledge, have the VWK gather all the aggro in the valley in the middle of the area (northeast from Port Sledge), and have the /R drop spirits. Keep chaining VWK (perma due to QZ) and watch everything die in an EoE bomb. Rezone and repeat. ~1min for 20-30 foes in NM.
The area in the south-east corner of Vulture Drifts seems to work pretty well - the southern entrance from Arid Sea. Make your way north killing Sand Giant packs, then once you're out of them retrace your steps. Zone out, zone in, lather, rinse, repeat.
Perma with bonder in Heart of abaddon. (Video: )
Spirit spam just outside Gate of Fear (in the Domain of Fear).
Go to Pogahn Passage and ask Jack of Truths for the Quest (you need Magrid). Just kill the Demon Spawn at the first flag. Ranger with degen build works nice (with speed boost skills for faster getting to demon) or others builds like spirit spam, degen mesmer/necro, warrior with big DPS. To farm here speed boost skills are recomended.