Stealing and dumpstering clothes works well. Just rememebr to donate some to places like the Salvation Army.

I've found some good online stores which sell non sweatshop clothes.

I am happy.

Also you can find responsible stores that sell fair-labor clothes from online sources, like www.greenpages.org.
Also, major companies like Nike and Disney with poor working conditions for their workers have made steps in recent years towards a positive change, under pressure from activists and consumers.
So you can make a difference in this fight, if you're willing.

Not all stuff is made in sweatshops. Look at the label. If it says made in the U.S.A. it is much less likely to be sweatshop made (although there are some sweatshops in the U.S.). It isn't that difficult.