Diana vs Cho'Gath

Hit with Crescent Strike (Q) before Lunar Rush (E): on a target marked with Moonlight, the dash has no cooldown and you can recast it right away.

Weave autos between your spells: after each ability, Moonsilver Blade (passive) boosts your attack speed for 5 seconds, and your third hit cleaves nearby enemies.

Cast Pale Cascade (W) before you engage: you gain a shield, then a second one when the last sphere explodes.

Cast Moonfall (R) in the middle of their team: it pulls in and slows nearby enemies, and hits harder for each champion pulled after the first.

Keep moving against him: Rupture (Q) strikes an area on the ground, and an enemy standing still takes a knock-up, damage and a slow.

Punish him when he goes for last hits: Carnivore (passive) restores health and mana for each unit he kills, and he lasts a long time in lane if you let him farm.

If you have range, keep your distance: his kit has no dash, only the slows from Rupture (Q) and Vorpal Spikes (E).

Don't stay in melee range at low health when Feast (R) is up: its true damage ignores your resistances, even if you're a tank.