Heavy Metal fashion, like most fashion among other subcultures, is used to identify one self as a member of that subculture.
The Metalhead typically has either long hair, or is shaven bald and sometimes short hair. Clothing normally includes band T-shirts and denim jeans or army pants. Other accessories that Metalheads may have are leather jackets, spiked gloves or wristbands, denim jackets, etc.
Among Power Metal fans, medieval, normally Viking-themed battle gear including armour, war paint, renaissance-style clothing, etc. are common.
Metalheads typically listen to metal and other forms of Rock Music. Most Metalheads (if Not All) like all kinds of metal rainging from Glam Metal to Thrash Metal to Black Metal and everything in between.
Unlike many other subcultures, Metal has little ideology as far as worldviews, politics, and society goes. The Metalhead subculture is based on music rather than ideology, but some ideas that are central to Metal ideology are anti-commercialism and anti-conformity. Anti-conformity in Metal is not against conformity itself, but conformity against ones real interests.