User blog comment:BlueDagger/Chekhov's Guns in Gravity Falls/@comment-5230858-20120817203735

In episodes, a couple are:

1. In "Tourist Trapped", when Dipper shows Mabel the page with the undead, he accidently flips to the gnomes page. This was a hint about the true identity of Norman. The incident with the leaf blower also seemed to be just a funny thing that was added, but it was what was used to defeat the gnomes in the end.

2. In "Irrational Treasure", Mabel eating old-timey butterscotch seemed to be irrelevent, but it helped the cops find her and Dipper.