You can buy your jeans from quality selvedge shops. There are many denim manufacturers to choose from that grow sustainable, organic cotton and weave/sew them in first-world countries that pay their workers livable wages. Obviously you'll pay more for these kinds of jeans – think in the range of $150 at the low end up to well past $500 for high end.

If you're into techier outerwear, you can look into the very popular Outlier (www.outlier.nyc) – again, you pay a premium but the textiles and sewing are made in socially responsible ways in socially responsible areas (I think).

I don't have a super comprehensive knowledge of fashion in this space though.