Well I am from India, so I cannot guide you on how to start a fashion business in London. But,what I can tell you is
Hang out at fashion shows a lot. You can probably find investors there. Even if you don't, you could still network with some popular people in your niche.
Also, try to start off with working as a fashion consultant. You get some clients that way and then you can use those client base to rope in genuine investors.
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