I am in the US so brands may differ...I look for JCrew, Banana Republic, Hollister, BDG, Loft, Ann Taylor and more, and keep my eye open for any surprising designer names. My style has become quite classic because I look for natural fibres, fine wool, cashmere, linen, cotton, and leather footwear.
I have some nice blouses and tops, a Lands End down filled winter coat, jeans, shorts, and trousers, and lots of footwear plus lots of cashmere cardigans and sweaters, one gorgeous French leather handbag and and two vintage Coach bags thanks to my local Goodwill shop, where pricing is done according to category and only occasionally according to brand.
I send the odd very nice work dress, skirt or shirt to DDs 1 and 2.
I am always on the lookout for Hollister, Anthropologie, American Eagle and Aeropostale items for DD4 and DN, and barely worn footwear for myself and DCs - found a pair of grey suede Ugg sneakers for DD4 two weeks ago for $14.99... My excellent snowboots were a find from last spring.
I also look out for gym wear in decent condition.
I have found many nice decorative things for my home plus scented candles and several books Also, recently, about two dozen cereal bowls and bread plates in Blue Willow pattern, matching what I already had.
January is a great time to pick up Christmas gifts that couldn't be regifted or returned, I have found.