Welcome to my guide! I play Dominion exclusively and was disappointed to find there wasn't a great build guide for Lulu. She's a very fun caster, with loads of annoying CC.

This build uses a hybrid on-hit/AP/CDR to capitalize on all her strengths. Her passive increases on-hit strength, her CC loves CDR for more spammage, and AP gives her decent burst with Glitterlance and Help, Pix!.

Pros
+Loads of Crowd Control abilities
+Good mixture of burst and sustain
+A fun kit with unique skills
+Hated by enemies


Cons
-She's a bit slow
-Squishy without appropriate defensive items
-Not high burst (like LeBlanc), and not high sustain (like Ashe)
-Hated by enemies

Marks: Magic Penetration to increase damage of both on-hit and spells
Seals: Armor for early survivability. With the proliferation of bruisers/AD with gap closers, her survival relies on mitigating enough damage until she's able to escape with Q/W/R
Glyphs: Scaling Magic Resist helps keep up the defense against other magic damage champions throughout the game.
Quints: You have two options here. AP for early burst, or Move Speed to make up for her lack of speed.

Building Lulu 9/21/0 gets CD/AP/%MPen from the Offense tree, and maximizes her survivability through the Defense tree.

Why one point in CD from the Defense tree?
With 4% from Offense, 25% from Nashor's Tooth, and 10% from Hextech Sweeper, you're almost maxed at 39%. Putting this one point gives you the 1% remaining at level 7. While another ~1% is wasted, you are saving money by avoiding another 15% CDR item instead of the Hextech Sweeper.

Pix, Faerie Companion (Passive)
Pix fires bolts at whomever Lulu auto-attacks.
This is what makes Lulu synergize with on-hit so well.
Glitterlance (Q)
Lulu and Pix each fire a slowing damage bolt.
This is your bread and butter. Escape, harass, burst, last-hitter all in one. Great fun to land once an enemy has escaped to the brush (because you still have vision from Help, Pix!/ Hextech Sweeper).
Whimsy (W)
Overpowered polymorph on enemy or decent speed steroid on friendlies.
As soon as the gates open, I cast this on one of my teammates to rush windmill, and after that will almost exclusively use this on enemies. The polymorph prevents them from attacking and using skills, and in combination with Glitterlance will turn back most enemies.
Help, Pix! (E)
Shields friendly or damages and gives vision on enemy. Passive and half of Glitterlance fires from target location for duration.
The second part of this ability is what makes it nice. I primarily use it as a damage spell on enemies, but then can cast my Q to hit targets further away. This is great for last hits on escaping enemies. The vision aspect is not necessary once you get your Hextech Sweeper.
Wild Growth (R/Ultimate)
Friendly target gains HP; slows and knocks back nearby enemies.
This is an amazing lifesaver ability. Pop this when you or a friendly's health is low and will die without intervention.

Regardless of which you choose, PLEASE put a point in the mastery that upgrades them.

Great Choices:
Exhaust - Can be used offensively to prevent an escape, but is much more powerful as a defensive spell. Not only can you escape more easily, but the damage output reduction is more than enough against burst mages that you will out-sustain.
Revive - A great spell for the initial windmill fight, and can help with a clinch capture late game. Expect to only use it twice, so make it count!
Heal - Because Lulu's only heal (essentially) is her Wild Growth ultimate, she is able to play a bit more of a support role with Heal.

Decent Options:
Ignite - When on a more offensive role, this helps Lulu get the damage to finish off the enemy or counter a healing/lifesteal/regen champion (Crit Sion, Dr. Mundo, Soraka, etc)
Clairvoyance - If you choose to skip the Hextech Sweeper, this can give you a good alternate source of vision. Great for catching gank setups.
Ghost - Great for movement, but you have your Whimsy
Garrison - Perfect for defending your point, or diving someone on theirs.
Cleanse - Great for stripping Exhaust/ Ignite when targeted or ganked.
Flash - Much less useful in Crystal Scar than in Summoner's Rift, but still not bad for an "Oh *%&^" escape

Don't you dare pick..
Smite - Really? In Dominion? The ONLY use for Smite in dominion is against a Promote'd minion, or an AD Malzahar.
Clarity - Grab a health pack if you need mana. Don't waste a summoner slot.
Promote - Are you really going bottom? There are so many better picks..
Surge - Low boost, low duration, longer cooldown. Ignite would be a much better alternate.

Starting items:
Boots + Prospector's Ring

Core items: It is important to note that they don't need to be built in this order. If you need more MR/Armor, get a Negatron Cloak/ Chain Vest early.
Sorcerer's Boots - Magic Penetration
Nashor's Tooth - Attack Speed, Cool Down, Ability Power
Hextech Sweeper - Ability Power, Cool Down, Vision
Malady - Ability Power, Attack Speed, On-hit effects

Remaining choices:
This is where it's important to customize your items to fit your needs.
Zhonya's Hourglass - Armor
Abyssal Mask - Magic Resist
Rabadon's Deathcap - AP (more burst)
Moonflair Spellblade - Tenacity (if they have tons of CC)
Void Staff - %Magic Penetration (if they are stacking MR)
Wit's End] - Attack Speed, Magic Resist, On-hit effects

What!?!?! This is Dominion, not Summoner's Rift. If you're 'farming', you better be pushing a lane.

Now if you're farming champions, I guess that's OK, but remember, Dominion is won by point captures, not kills.

With Glitterlance (Q) having a cool-down of just over 4 second at 40% CDR, you are able to spam this fairly well. Leading with a Glitterlance to hinder movement, auto attack once, then Whimsy (W) the enemy. Get another auto attack in, then Help, Pix! (E) yourself if the enemy is attacking you, or the enemy if they are running (especially if you don't have Hextech Sweeper yet). Continue to Glitterlance and auto-attack as you can, and recast Whimsy and Help, Pix! if the fight lasts long enough. Use your ultimate as an escape if needed.

Of course, in a team fight, you will be using these skills much more situationally, and reactively. Whimsy the non-tanks that dive your squishies, Glitterlance their squishies to allow a charge, Help, Pix! either as damage or to position the source of your Glitterlance. This can be used to hit the back row of their team by placing Pix on their front row (bruisers/tanks).

Lulu is a very fun champion with the necessary elements of Dominion: burst, CC, and the ability to build tanky. Her kit is both unique and exciting, and Whimsy is guaranteed to cause rage or your money back*!


*Only cost of viewing this guide will be refunded.