Ezreal vs Ahri

Land Mystic Shot (Q) as often as you can: each hit lowers all your cooldowns and adds a Rising Spell Force (passive) stack.

Detonate Essence Flux (W) with a spell rather than an auto: the orb deals its damage either way, but a spell refunds its mana cost plus a bonus.

Save Arcane Shift (E) to escape unless the kill is certain: it's your only way to reposition, on a 26 to 14 second cooldown.

Cast Trueshot Barrage (R) across the map to finish a fleeing target: it hits everything in its line, but deals less to minions and non-epic monsters.

Keep minions between you and her: Charm (E) stops on the first enemy hit, and without it her burst lands far less often.

If you can only dodge one pass of Orb of Deception (Q), dodge the return: it deals true damage, which your resistances don't reduce.

Play hard once she has used the dashes of Spirit Rush (R): she has nothing left to escape with, and its cooldown is 140 to 100 seconds.

When she roams, avoid walking through the jungle alone: Charm (E) then Spirit Rush (R) let her catch an isolated target by surprise.