After killing primary targets on Magelo list in Grimling Forest and Tenebrious Mountains for about two hours and coming up with none, I ask if anything but persistence and expanding targets in Grimling will help. Considering that many of these things are needed to do all of the Acrylia recipes, it appears there is a long slog ahead.
I got quite a few windstones killing Grieg's End mobs. Granted, I kill a LOT of mobs while XPing their on a TLP recently. They aren't a common drop.
I got all my Windstones in the Grimling Forest, killing Grimlings on the way down to Acrylia Caverns and the ones outside on the platforms, they are not common, but this seemed to be the best place for them IMHO, I tried quite a few other places, but this was the best for me. Good Luck
I farmed Twilight Sea elementals and aliens (Crag Ligi, Grol Baku, etc.). They are really low level (20's), so it's not a place to farm while xping, but a higher level caster can round up a couple dozen mobs and PBAE them all in one shot. As a Wiz, this is my favorite farming technique. Use the Staff of Temperate Flux to get agro while running around (instant cast debuff - can use the Staff of Viral Flux from the CotF achievement if you're not a wiz), and then blast them all at once. After doing that a couple times to clear the elemental island, I would do the same to the couple of alien islands in the main part of the zone before going through the underwater tunnel to the area with more of them. Then back to the elementals, which will have respawned by the time you finish there. Besides Windstones, I also got quite a few Ice of Velious, Chunk of Condensed Ice (arrows trivial at 268 with some acrylia shafts), and the Essence of Wind that is also for the acrylia temper. That's my experience and advice, anyway. Have fun Farming!
Caves in Grimling Forest. They don't drop often, but since the mobs are trivial you can mass kill. You should get a few each clear of the caves.
