- pay attention to your body language ("what am I saying with my gestures and posture?");
- only buy things you really love;
- spend on accessories;
- avoid "orphans" and "widows";
- when you buy something new, think about at least three items that you already have and can wear with it;
- always remember the "cost per use": if you pay 100 dollars for something you wear 10 times a year, each time you wear it you will be spending 10 dollars;
- be creative and try to modify your clothes.
Adapted from here.