Ok, I admit, I am not the best LOL player NA. But I can ensure that this guide can help you if you are a beginner and new to Irelia. I am an Irelia main in the name of Commonsense12, and I love this champ. Even If I don't know like animation cancel or anything, hope you enjoy this build :)

This build will hopefully help you get to an higher elo and help you master the Ionian will of blades. It will show you the basic Irelia mechanics to trading and how to rise back out while feeding.

Pros:

Bully if played right
extremely strong
Hard CC (2 sec stun/2 sec slow)
Excellent landing phase
A lot of people don't know counter

Cons:

Squishy if not building tanky
easily caught out (No built in escapes)
Easily countered by CC denials (Olaf/Master Yi)
Easily Bursted if not built right.

TF used to be the best item for Irelia. Now it's... okay. It has been changed and now Irelia benefits more from Guinsoo's rage blade.

Example Final Build
Greaves, Guinsoo's, TF, Borc, Randuin's and Spirit Visage
- This build is the generic build path that you should follow the most. This build will help you dish out a lot of damage.


Example Final Build No. 2
Mercury, Guinsoo's, Borc, Maw, Dead man's plate, and Spirit Visage.
- I didn't list this on the top because it's mainly situational. But the Mercury, Maw, and Dead man's plate will be able to get you out of sticky situations really well. This build is mainly for when you start to feed during laning.

Must take:
This summoner helps get away and adds much more mobility to this champ. It will combo well with your Q by being able to gap close really well and will help while either running or chasing in the Jungle.

This summoner helps TP into fights or out of finished fights. This summoner is good for most top lanes because since you are a toplaner, you will split push a lot, but TP helps you get good TP's into bot lane and help you pick up some objectives like dragon or a turret.

Consider:
Ignite is ok if you want extra damage and some extra power when one-v-oneing, but I would much prefer teleport and flash for mobility and being Irelia.

I usually try to go to lane really early. I advance to the third bush in top lane, where I stand on the edge. Whenever someone comes near the bush, I stun them and get a few good hits on them. It helps a lot, I start out always more healthier, and early harass helps me pull of some really good first bloods.

I tend to play aggressive against most top laners. It works out well for me, but it might not for you. If they are not that tanky, just All in when you think you can win a 1 v 1. If the enemy is like a Malphite or other super tanking champs, just play safe and don't tower dive if you have less than 50% health.

If you recall, TP to lane to not get back in cs. Make sure to last hit well.

If you are doing better, stay in middle of minion wave. The q that blinks will be such a pressure to your enemies, so they will always stay away. If they engage like a riven, Q and E them, then they will mostly run because of the Dmg and CC.

Ah... your Hiten Style. This is the bread and butter of Irelia. This helps farm, take down turrets, and just win lane in general. When the enemy is trying to pull off something fishy, activate your W. This will scare them off mostly

If you are behind, try to last hit with your q. If it doesn't work that well, try to jg for a while. Your hiten style's regen will help you do well. Grab a red buff or something and maybe a cheeky kill in mid with help from your midland. That start usually works for me.

Your Generic Combo (Under lvl 6)

Q to a minion to get reset - W - AA - E - AA - AA - AA - Q - E

Your Generic Combo (After lvl 6)

Q to a minion to get reset - W - AA - E - AA - AA - AA - Q - R - R - R - R - E

Splitpush at the right time. If your team is applying pressure mid, go try to split push top. One of the enemy will go top but you can easily take him. But after you take the enemy, 1 more enemy might come to top to defend. Since you tower dived, You should get out of there and try to escape/bait into the jungle. Once in the jungle, try to kill the enemy if they chased you out.

When your base is at danger, you could do what I call a sacrifice for your team. Tp top, and push in. They will mostly all come for you and then your team can push out the part that is in danger. If you don't want to sacrifice, stay at base and try to keep them at bay because you are pretty strong.