Goth, punk, and other ways of expressing yourself as a teenager isn't so much a way of expression, as a way to find others.
When I was a teenager, I never adopted a single style. I'd wear some trendy clothes, sometimes i'd adopt a very "goth" look, only without the makeup, othertimes I'd look like a little skater-punk. It was a fully psychological thing.
When I first started high school, my mother was still buying all my clothes for me, and she had me in the trendy "hip" clothes. This attracted the cheerleaders, the guys into sports, the rich, snooty people who could have nothing to do with anybody who shopped at WalMart. These people had VERY rich extravagant families who would go away to exotic places leaving their children in the care of an in-home maid/nanny.
That winter I took up skiing, which inevidably lead me to try snowboarding. I cut my hair, to a short "wash and wear" kinda style, I shopped at the "skate shops", which carried skiing/snowboarding gear in the winter, and made friends with skater/snowboarder types. I lost the trendy clothes, because chunky heel shoes and skirts didn't work for me anymore, and lost all my trendy friends.
My best friend at the time ended up dressing goth over the spring - it was a slow transition for her, but by the following school year, she was dressing like the "goth" stereotype. Suddenly everybody we were once close to hated her (and she was pretty popular for a while), and other goth/punk types, and I by now was a full-fledged labeled punk. My hair was always wild colors, my wallet was always hooked to a chain, I had the baggy pants and cute baby t-shirts advertising various skate companies, or dishwashing liquids, or with odd messages, such as "I steal music off the internet" (back BEFOR everybody else was wearing this stuff).
Goths and punks occasionally mingled and everybody else hated us. There were a few bad apples, but you see that in EVERY group of people (especially in high school) weither they dress "normal" or otherwise. I'd have to say, though, that I found the goth/punk groups to be the least judgemental and the most harmless. Most of them were pretty fun-loving and not at all depressing.
Well eventually we all went to college, or got real jobs and none of us still dress like that. But that's because now we don't have to dress a certain way to meet a certain type of person. Mannor of dress was just a way to make friends at that age. We had quite a few people who were goth/punk who hung out with us for a while, didn't like it, then the next day were dressed totally differently and hated goths.
Ahh the psychology of high school. I was making my psych thesis on it, but due to medical problems I wasn't able to finish that year of school.