(at around 10 mins) Brodie's comic book collection seen in the movie was director Kevin Smith's collection at the time (which has grown considerably since). The collection is what Smith was able to purchase back after selling his original collection to finance production of Clerks (1994).
The studio almost replaced Jason Mewes (Jay) with Seth Green. Kevin Smith insisted that Mewes should play Jay, but the studio made Smith take auditions for the role. Breckin Meyer also auditioned. In the end, all concerned agreed that Mewes was right for the part.
While shopping, Rene Mosier (Shannen Doherty) is seen wearing at least three different outfits. Doherty had a clause in her contract that stated she could keep everything her character wore, so she came up with the plan that her character would wear everything she bought.
Svenning was not originally supposed to be bald. Michael Rooker was trying to dye his hair gray for a better look, and decided that bald would work even better.
(at around 1h 3 mins) Originally, Stan Lee was not going to have a cameo in the movie. Kevin Smith had written a fictional Stan Lee-type character, but through a connection, Stan Lee was asked to be in the movie and agreed.
Kevin Smith: [Jaws (1975)] (at around 11 mins) TS was going to propose to Brandi at Universal Studios "after Jaws popped out of the water". Character names Brodie, Bruce, and Quint are references to the same movie.
Kevin Smith: [cousin Walter] One of the main characters has a cousin Walter who is sexually odd. Brodie Bruce's (Jason Lee) cousin Walter sticks cats up his ass. In Clerks (1994), Randal's (Jeff Anderson) cousin Walter broke his own neck trying to give himself fellatio. This cousin Walter is the same person, ergo Brodie and Randal may be cousins.
Kevin Smith: [comic books] Brodie is a comic book collector. There is a comic book store in the mall. Comic book Creator Stan Lee appeared in the movie. Brodie and TS discuss Superman's sex life.
Kevin Smith: [off-screen grab] (at around 1h 1min) When Ivannah (Priscilla Barnes) offers to let Brodie examine her, TS (Jeremy London) grabs him from off-camera, and pulls him out of the tent.