How about the music? I know, I know, don't analyze, so I'm observing that music has a lot to do with this movie. The name of the movie itself is based around a song. Dennis Hopper gets crazy when certain songs are played, namely Blue Velvet and that creepy-ass Roy Orbison song. The music switches drastically in the opening scene, starting out with very standard "happy" music while typical America is shown, and then switching as the camera pans down to the bugs. Most movies have quite a bit of music, obviously, but it seems to me like Blue Velvet had a bit more. It makes the drastic shifts of tone a little more obvious, and sometimes escalates the feeling of irony, or, if you're like me, confusion (i.e. girl dancing on top of car as Dennis Hopper freaks out).
Next time I watch the movie I'll really be paying more attention to the way Lynch uses music and what points he may be trying to emphasize with it.