Tristana vs Yasuo

Plant Explosive Charge (E), then activate Rapid Fire (Q): the attack speed helps you land the 4 hits that make it explode right away, at full power.

Hit from range and back off as soon as they come close: Draw a Bead (passive) increases your attack range with each level.

Chain your jumps in teamfights: Rocket Jump (W) resets right away on a champion takedown, or when Explosive Charge (E) explodes at max stacks on a champion.

Save Buster Shot (R) for the assassin who jumps on you: the cannonball knocks back your target and nearby enemies, and stuns them.

Hit him with a cheap attack to trigger the Way of the Wanderer (passive) shield, then start the real trade: otherwise, it absorbs your best damage.

If you have projectiles, save them for after Wind Wall (W): it blocks them all for 4 seconds, on a 25 to 17 second cooldown. Other spells go through it.

Don't stand right behind your minions: each one gives him a target for Sweeping Blade (E), and he gets closer to you with every dash.

Get out of the line of his whirlwind, the third Steel Tempest (Q): without a knock-up, he can't cast Last Breath (R).

Judge his threat by his crit items more than his level: Way of the Wanderer (passive) raises his critical strike chance, so each crit item does more for him.