How to be green about your clothes and your shoes:
1) Buy renewable and natural products such as hemp, cotton, wool, linen, and silk. Polyester and other synthetic materials use petroleum. Leather comes from pigs or cows which has a larger carbon footprint.
2) Buy organic materials like organic cotton and hemp which uses fewer pesticides to make. Or use synthetic materials made from recycled products.
3) Buy used. Because of the dyes, bleaching, and tremendous amount of water that it takes to make clothes and shoes, it is better to buy gently used clothing and to repurpose clothes that you have. You can donate clothes that you've outgrown and/or you can cut clothes up to be used as rags. Or you can also use the fabrics from clothing to make things like cloth napkins or place mats. Be creative especially if the fabric is still usable.
4) There are a number of programs world wide that collect old shoes and repurpose them. Here's a list of places: http://www.runtheplanet.com/shoes/selection/recycle.asp Nike will take used shoes and use them to make running tracks, basketball courts, and tennis courts.
5) There are also a few places on the web that sell shoes made from recycled products. Here is a listing: http://www.pristineplanet.com, http://www.jadeplanet.net, and http://www.terraplana.com, http://www.jambu.com, and http://www.sanuk.com
Note: I'm not paid buy any of these manufacturers. They are listed because of research only. I do not personally own any of their products. Buyer beware.