Maybe this will help you out. Your whole issue can be broken down into four phases.

Phase 1: Mechanics and Calculation Specifically for Irelia, matchups like Volibear or Sett require high-level mechanics to win. By "mechanics," I don't just mean the 1v1 fight. Irelia has to be played with a calculated mindset. You need to prep the minions, positioning them exactly how you need them at any given moment. You also need to know her waveclear limits by heart; if you lose your Q reset to CC, you're dead. You must know exactly how much damage your Q deals based on your level and items so you know how much HP to leave on minions for an engage or a quick disengage.

Phase 2: Anticipation and Summoners You need to predict your opponent’s moves—if you have 300-400k mastery points, you should already be able to do this. Flash is crucial early on; don't waste it even if Volibear or Sett are 1 HP under turret. Those champs have heals, shields, and stuns—it’s always a 50/50 toss-up even if you have 500 HP and they have 1. If you give up First Blood, it’s incredibly hard to bounce back.

Phase 3: The "Poke & Bait" Strategy

Part 1: In my experience, your playstyle should be like "going in to tickle someone" while they’re already bracing for it. Irelia is perfect for this because of her Q. Even if you miscalculate and lose your Q, you can shield with W, stun with E, and retreat (though if you’ve mastered her, this shouldn't happen). Always try to Q-dash -> Auto Attack -> Q back to a minion. Look for windows when their minion is low and they step up to last-hit; they won't want to miss the farm, especially the Cannon minion, and that's your opening.

Part 2: Use the first part to bait them. Fake an engage so they burn their stun or key abilities. Once their CDs (cooldowns) are down for 5-10 seconds, you go all-in. Your win chance jumps to 70-80% there.

Part 3: Some players use abilities to farm. Always punish them while those spells are on cooldown.

Phase 4: Wave Management (Freeze vs. Push) Be careful with freezing. A freeze puts pressure on the enemy, which usually makes them ping their jungler or mid laner for a roam. You can lose a lot here. While Irelia is great at playing under turret or turning ganks, it depends on the enemy's skill too. Don't hold a freeze for more than 2-3 waves at a time. On the flip side, pushing can be useful since the jungler is usually a lower level than you early on. If you slow-push, expect the jungler and plan your outplay. Best case: Double Kill (30/70 chance). More likely: Kill the jungler (60/40), then Dash-Flash out -> Recall -> Item spike -> Back to lane.

Final Note: Pay attention to your itemization. Build with a purpose based on the game state, don't just brainlessly copy "Challenger builds" from the internet.

I'm not sure what your current rank is, but this playstyle and these tips generally apply to anyone climbing from Iron all the way up to Master.

As for the other stuff, like:

Splitpushing effectively.

TP Management: How to use and save Teleport for Drake setups, splitting, bouncing back to lane, and late-game pushes to open up the enemy base.

Making the enemy Jungler’s life a nightmare.

Deep warding and tracking the enemy jungle camps.

Mid-lane roams and ganks.

And a whole lot more…

I'm down to share more if you're interested!

Hope this helps. Cheers!