Jhin vs Sivir

Save your 4th shot to trade: Whisper (passive) always makes it a critical strike with bonus damage, and each crit gives you move speed.

Fire Deadly Flourish (W) right after you or an ally hit the target: they're then rooted, and you gain move speed.

Place Captive Audience (E) in brush and along your escape path: the trap is invisible, slows the enemy who steps on it, then explodes.

Save the 4th shot of Curtain Call (R) to finish someone off: each bullet slows and hits harder on a wounded target, and the 4th is a critical strike.

Dodge Boomerang Blade (Q), then its return: it damages on the way out and on the way back, and it costs Sivir a lot of mana.

If you have CC, cast a cheap spell first, or fake a step forward: Spell Shield (E) only blocks one ability, and heals her if it blocks.

Back off when she casts On The Hunt (R): her whole nearby team gains move speed to engage on yours.

Don't leave her alone on a lane for too long: with Ricochet (W), her autos bounce between minions, and your wave, then your tower, fall fast.