I'm going to post my experiences with different brands and also ask about school shoes.
Next - I like the style of the cardigans but they tend to go bobbly.
The pleated skirts are very nice and wash / wear well. They also do nice track suits for PE.
Sainsbury - great polo shirts which stay white and wear well
Cardigans also very nice but although they don't bobble they do fade in colour.
Marks & Spencer - generally good quality - I have to buy skirts for dd3 from there because nowhere else does green.
John Lewis - do the best most hardwearing summer dresses. Also the shirts are very good. Unfortunately as my girls become older I'm finding the styles they do aren't as fashionable as other places though.
Usually we buy Startrite or Clarks shoes. This year I was wondering about trying Next shoes as I've seen some reviews saying they are comfortable. I also wondered about M&S. Does anyone have a view about that or do they all get similarly trashed?