I also have small feet...usually end up with 7 or 7.5, which means too large for "small" and too small for "medium".

I have never, ever had any success with cotton socks shrinking, or fitting in general, unless they are actually the right size in the first place...or a small will stretch without looking strange or wearing thin.

IIWY...to get out of the socks you have now...get a wool sock in a medium shoe size, and shrink the foot. I did this with my socks, and it worked out great.

-Sean