Carole1961 I find Outlet Centres excellent, in particular M & S for clothes, Pavers and Clarkes for footwear.
And if you know your sizes, eBay for new or nearly new.
I love the 'good labels' such as Phase Eight, Kaliko, LK Bennett, Hobbs but only buy these on eBay.
With regard to what to wear depends it greatly on your height/sze/shape and what you like.
I have my own rules for what (I think) suits me with comfort coming first. I find jeggings were ok with boots in winter but don't rate them for summer, the balance without boots looks wrong on me because I am bigger on top. I don't wear 3/4 cropped trousers as one leg is unsightly with veins, so I choose boot cut jeans, straight leg jeans, often roll up a straight leg cotton trouser to just above the ankle. I like ankle grazers for summer. For comfort I wear sneakers, trainers or a loafer. And always a top long enough to cover the bum.
Dressing up for me means a nice longish jacket, black or navy jacquard ankle grazers or tapered trousers and patent or suede flats. Very often a scarf/pashmina to finish off.
I did a big clear out and sold loads of my unused clothes on eBay.
Now I don't have a lot of clothes but every item is in use and fits.