In the city I am in, there is a shop that is known as the bundle's shop which sells used clothes imported. They sell at really cheap prices like 3 for 10 and it is usually packed with people who are looking for clothes that sell for such cheap prices.
The other way is to go to H and M and redeem those 15% coupons in which you can use to purchase new clothes the next time you come to the store. It won't be much but there will be some cash to be made.
If it's good and great quality, can sell on second hand sides like ebay. You can usually still sell for around half price of the original price. It's not too bad considering you do not actually want them anymore.