As mentioned in the general tactics article, the new Wood Elf army has a lot of flexibility when it comes to making a viable army. One of the strongest and coolest options is to carve a themed army out of the entries in the Wood Elf army list that are described as Forest Spirits.

For the most part, Forest Spirits are the ancient denizens of Athel Loren that inhabited the woods long before the Elves came along. Dryads, Tree Kin, and Treemen fall into this category. In addition to these ancient entities are a few Elves whose kinship with the forest makes them worthy of the Forest Spirit special rules. Only the Wild Riders of Kurnous and Wizards from the Glamourweave Kindred have earned this sacred status.

The Forest Spirit special rule is very powerful indeed. Firstly, all models with this designation have a 5+ Ward save against everything but magical Attacks (spells, magic weapons, etc.). Furthermore, all of their ranged and close-combat Attacks are considered to be magical. The final advantage of Forest Spirits is that they are Immune to Psychology. The only drawbacks are that non-Forest Spirits may not join Forest Spirit units, and the Immune to Psychology attribute means they cannot flee as a charge reaction. All-in-all, a pretty nice set of bonuses with only relatively minor disadvantages.

- Article by Ken Kennedy