When you look at fashion inspired by these sci-fi subgenres there is typically an emphasis upon 1970's punk fashion and its more recent off-shoots. Fetish clothing, spiky, dyed hair, tattoos, piercings.
Yet, when you read Neuromancer or The Difference Engine, you find nothing in these stories to suggest this fashion. The word 'punk' and how it is manifest in these books (the origin of cyberpunk and steampunk) is more to do with attitude rather than fashion.
'Punk' generates images of anti-establishment, irreverence of authority, breaking the rules, ignoring boundaries, anarchy etc. These aspects of punk are what you may find in the source novels.
Rather than revere technology, the characters treat it indifferently, casually. There is a saturation of throw-away technology evident from the very beginning on Neuromancer. The reader is bewildered by the dizzying descriptions of the future, but the characters are not in awe of their world.
In The Difference Engine there is a massive degree of detail pertaining to Victorian fashion, objects and technology. The punk element is not made manifest by spiky purple hair. Dyed hair is 1970's punk, not steampunk.
Each manifestation of the punk sensibility is relevant to the era in which it occurs. Victorian era punk styling is not going to take ideas from the 1970's. It rebels against its own era and the fashion should reflect this.
