[This is an excerpt from the current draft of my upcoming free ebook "Debunking the Seduction Community".]
Dressing well requires an understanding of fashion. Ideally, you belong to one scene or subculture anyway, and if you don't and are interested in one, you simply show up a couple of times, pay attention to what guys are wearing and you're good to go. If in doubt, ask people where they have bought their stuff. Most are a bit shallow anyway and love talking about themselves.
On the other hand, Mystery's “peacocking theory” presupposes that you have to wear certain items that make you stand out. Do a Google search and laugh at those pictures. In 2008 I used to go out a lot in London. “Pick up” was relatively mainstream, and those peope were usually extremely badly dressed. With my friend Terry --- the guy that got me started on fashion and who has now made his hobby into his profession --- I used to play the game “Spot the PUA”. It is great fun and maybe you should try it to.
Typical “peacocking items” include: furry hats, goggles, neclaces and bracelets in all shapes and forms. I have heard of people wearing feather boas, fur coats, pink suits, fishnets as tops and plateau boots, all in an attempt to stand out and to signal “immunity to social pressure.” Those extremes may be less common nowadays, but go to any mainstream club in the typical pick-up epicenters, and it shouldn't take you too long to see such people. Thus, the message is: if you look as if you don't belong, then you don't belong.
Forget "peacocking" --- work on developing your style instead.