Hi, I'm 42 also, I like to think I'm stylish, I'm interested in fashion, and have really made an effort in the last year or 2 to not be 'mumsy' as, post DC, I was mostly interested in practical, comfortable clothing/footwear (my mumsy years).
My style can be described as 'rock-chic' (not 'chick', did that in my 20's 
). I take inspiration from Kate Moss, Emmanuelle Alt & Charlotte Gainsbourg. I mostly wear skinny jeans with a fitted longish t-shirt (long sleeve if cold) and drapey cardigan, biker style waxed jacket. Footwear is embellished flats, either ballet pumps or sandals and black biker boots or ankle boots.
Most of my clothes are understated items but in any outfit, one that is more standout like embellished or animal print. So I like detailed shoes or sandals, really after some snake boots at the moment but ideally black or grey love these. My legs are my best feature so I like skinnies with detailing, eg zips, like these. If my top is pattern then will wear plain understated other items.
My favourite range is Mint Velvet but its above my budget. So I mostly look for similar but cheaper items from Next, but avoiding their patterned 'typical next items', good for jeans, H&M, think they do quite stylish clothes at a good price, good for 'going out' tops and quirky trousers/jeans with detailing. Dorothy Perkins for t-shirts/basics, Warehouse, for 'evening out' clothes mostly, I like this top and for casual wear, I would wear this top with some grey or denim blue skinnies, or for night out maybe with a pleather pencil skirt or coated black skinnies. Love TKMaxx but need to be picky as there's lots of rubbish with a few gems.
I always pay a bit more for footwear so more likely to buy somewhere like John Lewis for Dune, Bertie or Carvela boots/shoes.