Saw a link to this in the comments section at IMDb.
1 drink every time someone drinks
1 drink every time someone says “Nine”
1 drink every time you see the number nine or can make the number nine from something on screen
1 drink every time you see a pug dog or a picture of one
1 drink every time you see the main character’s green friendship bracelet
Note: I don’t actually recommend this, because you’ll probably get alcohol poisoning.