The comic Luann (here Luann Againn), by Greg Evans, has a character characterized by interest in physical appearance and lack of interest in things academic. Her loss. But she’s a good example of what not to do, so that’s a good thing, I guess. Does her mistake jump out at you? If you’re a regular reader of this humble site, it should.
Right! When you compare two things, you use the comparative form, not the superlative. It’s “better,” not “best.” And when you’re not comparing anything, use the positive form, in this case, “good.” Poor Tiffany.