The backbone of my wardrobe (augmented by last minute Cos and Zara!) is from more blatantly designer-y brands, (Margiela would be a good example,) though I'm not loyal to any particular one, and rejoice just as much in a TK Maxx find nowadays as I did in DSM in a former City life. Often, before the Toast frock disaster*, I used to worry that such determined perniketiness was mere conceit on my part. But now I know that the aim is always to be able to recognise myself in the mirror ...
*Everything else I've bought there over the past fifteen years or so has been gorgeous, but, IIRC, almost always bought in store. I find the clothes don't lend themselves to screen guesswork.