I found this review of a Psy-trance party. Written by an outsider exploring the scene.

The whole article is him mocking and judging the people who go to these parties. The "nu-hippes".
But it gives a good insight to what goes on at these places, even if he did enter the party with a closed mind.  

"As easy as it is to mock the trustafarians and eurotrash hostel-hoppers that frequent its events calendar, psytrance really is a counter-culture in the truest sense. The music is harsh, the clothes are weird, the drugs are strong, the best parties are illegal. This isn't a scene you can enter half-heartedly; nobody is having their birthday drinks at places like this – it's too intense, too esoteric for the casual partygoer. If there's an entry level version, this party was probably it and it was still one of the most confusing and unusual parties I've ever been to.
Psytrance deserves its place in our cultural landscape because it remains one of the few subcultures that trendy Stoke Newington dads just won't get. They might get Kendrick Lamar or Jam City, but they won't ever "get" Psycle Lane. It must have its lineage, but I'm fucked if I know what it is and it does feel like a weird animal that just showed up one day without anyone knowing where it came from – a totally different club beast that even people with Superclub loyalty cards probably can't hack."

http://www.vice.com/en_uk/read/a-big-night-out-ata-psy-trance-party