Take a sip whenever you see the word "Corruption" or variations of it (Corrupt, corrupted, ect.) on FNF-related content such as this page. Say goodbye to your liver if you plan on doing this.
The series itself
Take a shot if the video you're watching uses a remix of a song in the vanilla game. Take two if it instead uses a completely original song.
When a corrupted character's corruption starts to revert (Such as with Boyfriend and Pico in Weeks 3 and 4), take a drink. MAJOR warning for Week 7 when Daddy Dearest reverses the corruption constantly.
When Monster appears in the windows during Week 2, drink.
When the background starts glitching in Week 6, drink. Not recommended for "Treacherous Thorns" or "Roots".
During "Deathmatch", take a shot every time Daddy Dearest's opponent is swapped.
Take a drink to pay your respects when the following text shows up: "(insert name of opponent here) was overpowered by Corruption."
Drink until you get alcohol poisoning when The Stinger for "Deathmatch" appears, where "the world was overpowered by Corruption". Finish your drink when Soul Boyfriend appears, grinning at the camera.
Take a drink every time Soul Boyfriend appears on screen. Take two if he pulls out a guitar.
Down the whole glass in victory when The Stinger for the final video of Week 8 appears, when Soul Boyfriend and Boyfriend shatter the corruption realm through The Power of Rock.