@Leilanii - I'm not particularly loyal to one store and I mix things from all over the place. Often I can't find exactly what I'm looking for, so I'll look on ebay or in charity shops (when I have the chance). For example, I wanted some trainers with pom-poms on them, but don't like any of the ones currently available (and am not prepared to pay designer prices for such a 'fashion' item). So I found a pair of trainers I liked and found poms poms on Etsy and clipped them on.
Places I use fairly regularly for fashion-type items are ASOS, Zara, Topshop, Zalando, Bon Prix, Boohoo, Miss Selfridge, La Redoute (also brill for duvet covers and bed linen!!), Chi Chi for occasion dresses
For basics I use Uniqlo, M&S, H&M, NAF NAF, occasionally Benetton
And for neutral staples (coats, boots, bags etc) I often buy designer or technical, for e.g. Marc Jacobs wool winter coat, Burberry trench, Canada Goose winter parka, Musto wool pea coat (which I changed the buttons on as I wanted silver, not navy), Mulberry for bags, Prada black patent ankle boots etc. I try to buy these out of season or in the sale at net-a-porter, Selfridges, Harvey Nicolls etc. to avoid paying full-price if possible.
Sorry, this turned into a bit of a long post!