I almost always wear a size 8 shoe.  Based on other reviewers' recommendation, I sized up and ordered a size 9.  When I received them, they were wayyy too big!  Luckily, Amazon has free returns for these, so I sent them back and got a size 8.  The size 8 fit me perfectly!  For me, going with my usual size was the right decision.

PS:  I was surprised that my shoes came with an extra pair caps for the heels. That was a nice.