This is the build I use with Irelia in 3v3 matches. It has decent survivability, excellent for 1v1 and occasionally 2v1. This is also the first guide I have submitted, and I am open to feed back.

I use strictly attack speed runes. They work really well with the critical strike and lifesteal from items, and help with lower level ganks, in conjunction with the stun from your E. If you are having problems with survivability you could sub out for HP Glyphs or Quintessences.

Masteries are just general AS/AD offensive runes, with utility for the extra gold, use of the Ghost Mastery, and the extra experiance while laning. Irelia having a level advantage over her enemies helps immensly.

You could substitute the extra gold mastery, to get 3/3 in the armor penetration mastery in the offensive tree.

The first item I buy at the start of a match is Boots of Speed for the increased movement speed for farming and early ganks, with two healing potions and one mana potion to stay in the lane longer. With those potions and the masteries I can hit around level 8, and a little over 1000 gold by the time I have to go back to base. The second item I buy is the Frozen Mallet. HP from it gives you an extreme amount of HP for lower levels, and the slow helps when ganking. Now is generally a good time to finish your boots. I find the Attack Speed benefits more than the reccomended Magic Penetration boots. The third item I get is either the Recurve Bow or the Vampiric Sceptre for Stark's Fervour. The Vampiric Sceptre gives you an easier way to farm, but the Recurve Bow helps with ganks and killing towers. After Starks you CAN get Phantom Dancer for the extra movement speed to get aroudn the map faster and chase down opponents, or you can start building Infinity Edge, or a tanking item if you are having more survivability issues. You can finish the next three items in any order you would like.

Boots of Speed > Frozen Mallet > Beserker Greeves > Starks > Phantom Dancer, or Infinity Edge, or Thornmail/Banshee's Veil

Personally I use E first to instigate ganks or to stun to prevent ganks. It can be used to slow people as they try to run away, or a stun when you get lower HP to use the attack speed runes to hit more often. The next ability is Q for the charge to chase down enemies, it hits relatively hard, and has 50% reduced mana when you killing blow minions with it. I grab those over Hiten Strike because the heal from it is almost neglable anywhere mid game, and the extra damage is also minimal. Irelia's ultimate does a fair ammount of magic damage, with four charges that are aimed at your current cursor location. 20% of the damage dealt heals you. Best time to use it is half way through the fight to gain from the life steal, and whenever their are minions around as you can hit them and gain HP from all of them.

I use Ghost and Exhaust as they can be used for ganking, or survivability at any level. You could sub one of them out for flash if you are exceptional at using it, but I have issues flashing over walls. You could also get Ignite to prevent healing and the extra damage during ganks.