I don't, but DD's friend's mum was most surprised when I told her earlier today that I don't. She then went on to tell me that at the end of every season she totally re-stocks both her DCs wardrobes with new clothes for the coming season and gets rid of things from the previous one. She also buys them 3 or 4 pairs of shoes per season.
She was genuinely shocked when I said that I don't do this, and things get given to the charity shop/Ebayed when my kids have grown out of them and not after just 3 or 4 months' wear. She was even more shocked when I said that DD will be going back to school in September wearing - shock horror - the shoes I got her in June, as they still fit perfectly and look new.