That's the point. Looking like a non-nerd sounds like selling non-apples to me. One possible way to “look like a non-nerd” is to look like a '80 skateboarder, but that wouldn't achieve your actual goal, so what you're actually trying to do is more complicated than that.
And what do you mean by “nerd” in the first place? Someone with a very high IQ? Someone with poor social skills? Someone who studies or works in a hard science or maths? Someone who couldn't play football halfway decently to save their life? Someone who is into certain particular games and works of fiction such as (say) Dungeons and Dragons or Star Trek? Only a few of those things would I want to advertise the opposite of via appearance. (Your age, gender and social circle are also relevant to that.)
This is a repository for major, life-altering mistakes that you or others have made. Detailed accounts of specific mistakes are welcome, and so are mentions of general classes of mistakes that people often make. If similar repositories already exist (inside or outside of LW), links are greatly appreciated.
The purpose of this repository is to collect information about serious misjudgements and mistakes in order to help people avoid similar mistakes. (I am posting this repository because I'm trying to conduct a premortem on my life and figure out what catastrophic risks may screw me over in the near or far future.)