I think of two main lessons.
1) Letting people make their own choices about clothes - we had battles over clothes for a while until I was about 9 but then Mum let me choose my own looks and pieces. I put together some pretty strange looks but I was happy to have that independence. I had a strong desire to wear jeans and cords and more sporty style clothes and she was keener on a Laura Ashley style for me. A very happy moment though was when she arrived home from a trip to Australia with two tracksuits for me when I was 10.
2) The power of wearing colours that suit you. Mum was an autumn - fading to a soft autumn in her later years. She always wore muted purples, browns, olives, warm navies, teals etc and avoided black, grey, cool pinks and the colours that did not suit her.