This is my first guide, im making it off experience of trial and error, trying builds and adapting my own to it, if you need anything cleared up, write in the comments please. If this guide disapoints, im sincerely sorry for wasting your time, but please try this build before hating or rating. Thanks.

Flash is very good, yes, but i've gotten better without it, in my opinion when its up you get to cocky and go somewhere you shouldn't. "I'm fine i'll just flash away" and in my opinion, thats a waste of a summoner spell, Remember, these spells are my opinion, feel free to adapt them however you like. Lets start with a list.

Reccomended spells:

Ghost(Get back here)

Flash(For oh sh** moments or "Let me hit you" moments.)

Ignite(I've gladly got someone low, ignited them, and ran back to my farm, it saves time, mana, it counters healers and life stealers and is great to kill from the grave, i love it)

Good spells:

Exhaust(I feel as though Q lets me get to them, but feel free to take this, its VERY usefull for alot of matters)

Teleport(If you want to hold a lane, gank a lane, farm a lane, whatever your needs, this helps it)

Clarity(I feel as though its useless for irelia when you have trinity force, but it also helps your team, dont forget that.)

Heal(I think her W and R covers this)

Fortify(Leave it to the tank)

Clairvoyance(Leave it for the support)

Bad/Useless spells:

Smite(Your not jungling)

Rally(I havn't seen a good use for this so far, You might know a use, other than tanking towers)

Cleanse(WTF?! Do you know who your playing?)

Revive(Who said you can die?)

If i missed any, post below, thanks.

You have no idea how many times these runes have saved me, defense runes work wonders, and the Armor pene is great, So many reasons why these own, i think you can think of the reasons, self-explanatory, Your not squishy and you hurt like hell! :)

I feel as this gives you a great boost to movement speed, cooldowns, a boost on ghost(If you Don't plan on using ghost, change this point to less time dead, masterys are for you to adapt around your summoner spells and play styles, don't take my word for it, change it to how you like it) but i feel as though this is a godlike mastery, but its my opinion :)

I just love my Q, although E is reccomended, i feel as though Q will do alot more for you while doing damage, E is absaloutely great too and does a nice stun to juke with etc, R you need to get asap when your that level, its so usefull, for some reason every enemy runs ****less when i start throwing it, like they dont know what irelia is or how to counter her, i use it to farm, scare enemys, defend, life steal, damage and pushing, its great, and W is amazing to activate before you iniate, for the extra damage. Remember, Q cooldown resets if you kill an enemy with it being the last hit.

I start with regrowth pendant and a hp pots, to stay in lane, and farm nicely, Then when i go back i make sure i have enough gold to buy boots (Tabi or merc depending on the enemy team) Philosophers stone and heart of gold, then i get trinity force (Sheen--->Phage--->trinity force) This gives a massive boost to your early/mid game.

Now it gets real.

If your going really tanky:

Gaurdian angel (A revive, magic resist AND armor, so great and cheap for 2 defenses)

Force of nature (Magic resist, movement speed, health regen, It's great!)

Thornmail (If they are AD/AS power houses or if the AD's cause you problems)

and randuins omen or shurelya's reverie (Or get both of these and forget thornmail, replace thornmail with Shurelya's and then get randuins after it, This is a much better build, but it depends on who your vs)

These items depend on who your going against If you want more damage and still be very tanky:

get both Hexdrinker and atmas together if they have a mix of AD and AP.

Hexdrinker (Get this first if theres alot of AP, or get this and force of nature if its only AP (force of nature replaces atma's))

Atma's impaler (Get this first if theres alot of AD, if theres only AD, get this and gaurdian angel or thornmail, it does wonders)

Randuins omen (This builds off heart of gold, it has regen, an AoE slow, alot of armor (Which is why you probably dont need thornmail instead of gaurdian angel as said above)And health for your atmas!)

Shurelya's Reverie (This builds off your philosophers stone you got early game, this gives regen, an AoE movement speed and health for your atmas, if you dont have atmas, just generally get this anyway, its great.

There is also plenty of other items that are of great use to irelia, but these are the ones i like. Whats not to love?! :)

Remember, irelia is a great solo laner, but that doesnt mean shes a bad dual laner, she is absaloutely amazing for both.

Early game:

Farm your *** off, harras with Q if you feel safe doing it(Q a low hp minion, then Q to a enemy champion, it hurts) Get kills if you can, this is a rather peacefull part of the game for me, unless im being pressured, but they usually dont target you if your dual lane because of your item and resistances.

Mid game:

Gank when you can, but if you cant, dont sit around wasting time, experience and gold, you need to be doing something almost all the time, dont be afraid to iniate, but dont if it will get you killed, more time wasted for an unnecisary death.

Late game:

(my idea of late game is 20 minutes+ even if your not full item build, your strong enough to go get killing!)
You should have a reasonable amount of kills/assists, little to none deaths from mid game and early game under your belt and atleast 80+ minion kills. you should have trinity force and maybe one or two of the other items, This is when you dominate, if you dont have any of that, dont worry, just go farm and gank when you can. In teamfights, go for the squishys and the enemy champions who cause the most problems, Needs to die and has a massive price on his head, NEVER waste a spell hitting the tank, unless hes the last alive, then go slaughter him too.

I will be adding pictures if this guide becomes more popular which will make the reading part of the guide, so much easier to understand :). I don't feel the need to yet though since it's a fresh guide and who knows how it will go, its my first guide for a champion i love playing and would never get bored of.

Thanks for spending your time checking my guide.

Remember to post in the comments anything you don't like, need clearing up, and your opinion, please remember this is my first guide i'm sure i missed something important, if you need anything, post it in the comments, it will help alot