The tagline for American Beauty is "Look closer," so you don't need to watch even a minute of the movie to know that looking past the surface is going to be important. In fact, that message is so key that it also appears as a little Easter egg on the wall of Lester's cube at the job he loathes.
Why is this message so central? Well, Lester's decision to stop caring about superficial stuff (read: appearances) in order to explore what he really wants is the driving force of 99% of the film's drama.
All of the characters struggle with the way others see them and with the picture they present to the world. Lester's big discovery is that once you can get past the superficial stuff, that's when you get to actual beauty.
Questions About Appearances
Does Lester truly ever escape from caring about appearances? How do we know?
Are there any characters who don't struggle with trying to keep up a certain appearance? If so, why are they exempt from that struggle?
Do you find Frank's big revelation regarding his hidden sexual orientation realistic or not?
Chew on This
Ricky is the only character who is completely comfortable in his own skin and presents a completely "true" face to the world.
Ricky is no different from the other characters in terms of having a public vs. private persona—sure, he only has to use the fake one with his father, but he still has to pretend to be someone he's not in order to survive.