I did this build because i was boared so sorry if something is wrong.

This Build that i made is for AD enemy team if the enemy team have more AP Champs You should buy the Force of Nature and not the R.Omen

Pros
*Her W gives you not bad health regen.
*Her Ultimate can keep her on the lane on full health for a lot of time
*Good Ganker
*Can Jungle (Not recommend you)
*Have True damage buff

Cones
*Not realy effective in early game.
*Her stun only stun if you are on lower health than your enemy.
*Not realy good on lvl 1 Fights

Jungleing*
In my opinion Irelia isn't the best jungler, but u can Jungle with her if you want.

In Team fights your part of work is:
*Use your ult that way that you hit all enemys on the other team (try 2 do your best there).
*You should Jump too theyr carryes qith Q make damage and stun with E, do that all the time.
*Play agressive with irelia dont be afraid if take too much dmg because if u are lower on health that your enemy you can stun him.

Irelia is realy good on farming, her ultimate can fastly clean big waves of minions very fast. Her Q Is amazing last hit spell that don't waste you a lot of mana ( Only if you kill the minion ) so don't be afraid use your ultimate for kill creeps because that have realy low cooldown.

I'm good as irelia on my opinion, this is my way 2 play her and i like it.