Go on-line and check out the Gee's Bend quilters. You'll see that they used only old clothing and their quilts are now in museums because of their beauty and creativity. There is an effort in the works now which encourages us to recycle many of the things we usually throw away.
I made a CrazyQuilt wall hanging out of old clothing and i cherish it. i included pieces from the dress I wore to my son's wedding; the blouse i wore to my Mother's funeral,etc.. It becomes very personal when you look at it.
Go for it!!