#1 Have a set budget
And stick to it! You can easily get carried away when you are in the store, thus, setting a budget is a must. You may also just bring cash and leave many of your credit cards at home so that you can resist the temptation of swiping the plastic money one too many times.
#2 Stick to your intended purchases
You must take an inventory of your wardrobe – what you have, what you need, and what you can afford to buy as well as what you can do to recycle/reuse items – before shopping for clothes. You should then list down your intended purchases and, just as with your budget, stick to it instead of being tempted to buy the latest fad in fashion.
Keep in mind that your clothes do not make you, so to speak, as well.