Miss Fortune vs Varus

Fire Double Up (Q) at a dying minion in front of a champion: if the shot kills the minion, the bounce onto the champion always crits.

Switch targets often: Love Tap (passive) adds damage on each new target, and lowers the cooldown of Strut (W).

Activate Strut (W) to get in position before Bullet Time (R): you instantly gain its max move speed bonus, plus attack speed.

Cast Bullet Time (R) on enemies who are CC'd or bunched up in a chokepoint: it's a channeled cone, and each wave can crit.

Back off after taking a few autos: each one applies a Blight stack from Blighted Quiver (W), and his spells detonate them for damage based on your max health.

If you can engage, go in while he charges Piercing Arrow (Q): charging slows him, and he has no dash to escape.

Get out of the Hail of Arrows (E) zone fast: the desecrated ground slows you and reduces the healing you receive.

When an ally is caught by Chain of Corruption (R), move away from them fast: the corruption spreads to nearby champions, but dies out if you get far enough in time.