I’m going to assume you’re more interested in what women over 30 are wearing, not teenagers. So based on my daily movement between east London (cool mums) and central London (work), these would be my main observations:
Shoes: very sporty, battered trainers when not doing any sport. Chunky black boots. Chelsea boots. In my corner of east London converse are popular again.
Coats: long wool coats worn open, in black, grey or camel. Duvet coats.
Jeans: cropped wide leg or slightly baggy high waisted.
Knitted, ribbed beanie hats.
Bags: anything goes. I genuinely don’t see many people using the Uniqlo style bag outside of soft play and travelling, but I might just be immune to them now.
Other things: oversized shirts, wide leg trousers (not jeans), BIAB nails with bright colour tips, sportswear as normal clothes, slightly oversized knits - often over the oversized shirt, multiple fine gold necklaces, hoodies under a smart coat, sport socks pulled up over leggings.
Caring about what you wear, wanting to look stylish, has too long been seen as a stick to beat women with. We should reclaim vanity as something to be proud of, in the same way that being house proud isn't derided.
Have a wonderful time OP.