Many people will give their clothes away to other people or Goodwill before they will make the effort required resell them. I have personally never understood that way of thinking, but you can benefit from those people. A few, like my mother, started to take her own clothes in, but I found for the most part people would rather give their clothes to me, even when they didn't have extra money to buy new clothes. So I started taking in other people's clothes and profiting from their decisions to clean out their closets. Then I started shopping at garage sales.
Many people practically give unwanted clothes away.
You can find very good deals at garage sales, especially if you go right before they close up for the day. You can buy clothes there, either for yourself or your children, or you can buy them solely for the purpose of re-selling them. I only recommend doing this, however, after you have been taking your own clothes in for awhile and find out what types of clothes the consignment store will accept. The consignment store reserves the right to not accept clothing that do not meet their standards. The store I shop at will donate unwanted clothes to charity for you, if you wish, if they will not accept any of your clothing.