Here are some of the possible army options with Night Elves.

Mixed troops
While many Night Elf players focus entirely on either Archers or Huntresses, you can benefit from using mixed troops. You'll find that at later stages of the game using mixed troops becomes more important. Bring some Glaive Throwers along as well as Dryads to slow enemy units and to remove spell effects. Druids can also be useful for Roar and Faerie Fire.

[ Click to Enlarge - 171 KB ] In an FFA game, the green Night Elf player uses Chimaera, Druids of the Talon (for Faerie Fire), Dryads, and two Heroes.	[ Click to Enlarge - 194 KB ] In the same FFA game, this Night Elf player uses Bears, Archers, a few Dryads, and Heroes.

Mass Huntresses
Mass Huntresses is a common plan when you are facing Ghouls, Grunts, and Footmen. They are very effective in large groups. One problem with mass Huntresses is that they have no air attacks. If the enemy goes air, they can finish them off without being able to respond. But the Night Elves can quickly convert to Archers and still use the same upgrades from the Huntresses. You can also add in a few Archers with the Huntresses. Huntresses are weak against Riflemen, enemy Archers, and other ranged attacks. You will have to finish those units off pretty quickly to win. Mass Huntresses work in many cases but if the game reaches latter stages you may have problems against Tauren, Knights, and Abominations. In those cases you need to use Mountain Giants, Druids of the Talon, Dryads, or Bears.

Mass Archers
Mass Archers are especially effective in team games where your allies can build the melee units which soak up the damage. Your ally could for example build Grunts, Footmen, Ghouls, or Huntresses and your Archers can back them up. Mass Archers are also effective on maps with limited pathing (or tight spaces). In those situations the enemy won't be able to get all of their units attacking at once. Mass Archers also transition well until Hippogryph Riders. But be warned that mass Archers can die very easily against mass Huntresses or when the enemy uses spells like Blizzard, or Chain Lightning. Be reminded that focus fire is key with Archers.

Huntresses + Archers
Huntresses and Archers are a good combination. The Archers can hang out behind the Huntresses and bomb enemy units with superior damage.

Mass Cyclone/Druids of the Talon
A very powerful strategy is to build up a large group of Druids of the Talon then use Cyclone on the enemy. By raising the enemy into the air you're effectively removing them from battle. Using Cyclone you can reduce the army to a small group that is easily overcome. This strategy is easier to pull off in 3 vs. 3 and 4 vs. 4 games where allied players can protect you until you can create a large group of Druids of the Talon. It also requires a lot of talent to effectively use Cyclone on every unit in battle. Some players are very good at this while others try it and fail due to lack of clicking skills. Cyclone can be dispelled so it can be beaten.

Druids of the Talon are also very useful for Faerie Fire which can be very effective in team games.

Mass Dryads
Building a large group of Dryads can be an effective strategy. Dryads can slow enemy players so you can use them to hit and run. It can be difficult to build up to mass Dryads. This is usually done by sending a Demon Hunter or Keeper of the Grove to use hit-and-run attacks on the enemy town. This will distract the enemy while you build straight up to Dryads. Build a Hunter's Hall, and upgrade to Tree of Ages. Build two Ancients of Lore. Now begin making Dryads out of both Ancients of Lore. This can be a risky strategy because if the enemy attacks you in force, you won't have anything to respond with besides your Hero. But if you can build up without being hit, this can be very effective. Remember not to go mass Dryads vs Huntresses. To use the Dryads effectively you should have each Dryad attacking a separate target to slow them, then use hit-and-run attacks, never letting the enemy catch up. This strategy is often more effective in 3 vs. 3 and 4 vs. 4 team games than in 1 vs. 1, and 2 vs. 2 games.

Archers or Huntresses THEN Mountain Giants/Bears
While you can try to go straight up to Bears, this is very risky. You might be able to pull it off in a team game or if you can keep the enemy from attacking you by harassing them with your Hero, but that is very risky. A safer plan is to build Archers or Huntresses with 0 upgrades, and build your way up to Bears. Build two Ancients of Lore so you can research upgrades and train a Bear at the same time. You will then probably want two Hunter's Halls so you can research two upgrades at once to build up the Bears faster.

Bears and Archers are a good combo.

Mountain Giants + Archers
This is a good combo. You can even bring in some Druids of the Claw to cast Rejuvenation on the Mountain Giants.

Mountain Giants + Dryads
The advantage of this combination is that it is immune to AOE spells such as Blizzard. Only the Heroes can be hit by those spells.

[ Click to Enlarge - 161 KB ] Mountain Giant + Dryad Combination

Archers + Druids of the Talon
Druids of the Talon cast Faerie Fire on the enemy while Archers using Improved Bows and focus fire quickly pick off enemy units.

[ Click to Enlarge - 159 KB ] Druids of the Talon + Archers are commonly used midway into the game.

Faerie Dragons + Dryads
With a descent frontline ground army consisting of perhaps Huntresses, bears, Mountain Giants, and/or Archers. You can use this combo to wreck havoc.

Some enemies (especially Human, Undead, and Orc) rely heavily on casters. Both of these units, the Faerie Dragon, and the dryad are meant to counter casters. But together they have a far more potent power.

At the start of a battle, have your Dryads in the rear with their autocast of abolish magic turned off. Once the battle starts fly in a pack (2-4) of faerie dragons to over the enemies casters and/or heroes. Activate mana flare. Then activate the autocast of Abolish Magic. The Dryads will begin to abolish buffs like bloodlust and debuffs like slow. The enemy casters will compulsively (autocast) begin to cast the spells anew but now they will be taking fierce damage (3 per 1 mana) from mana flare.

This strategy makes the very best use of the anti-caster capacity of both of these units.

Counters
This strategy can be countered by deactivating autocast if you think a Night Elf player is going to attempt this combo. And targeting your own spells with casters that have enough life. Or, stop using spells during the duration. Or, attempt to kill the faerie dragons. Be carefull though, dedicating too much firepower to the well protected flaring faerie dragons can leave your ground forces weak to the rest of the Night Elf army.

Perfect Mixed Troops
Build a few Mountain Giants with the skin upgrades. Have some Dryads to cast dispel. Bring a few Archers. Bring a few Druids of the Claw to cast Roar and Rejuvenation and possibly a few in bear form. With this mixed force you can respond to a lot of different types of attacks and use Taunt to draw enemies away from weak units. This is most useful in Solo games.

Chimaera
Some players attempt to mass up some Chimaera. This can be an effective late game strategy if you're not facing someone who is massing Crypt Fiends with web or anti-air units like Archers, Dryads, or Riflemen.