In Southern California there are always those days where you are not sure if it will be hot or cold. Nevertheless you make a decision and its wrong! Yea, that has happened to me one too many times. I have found a way around this issue.
On these type of days I combine light fabrics with shorter length shirts/skirts and mix them with thicker knits and warmer shoes (in this case some knee high boots).
Give it a try! All you have to do is balance the thicker/warmer pieces with some light/flow-y items.