Pilates Problem
 

I have a terrible time standing on one foot! I can't hold the poses because I fall over. Any suggestions?

Don't do it!

Try just standing on tiptoe of the one foot that would ordinarily be off the ground -- this is what I'm doing in yoga.
As I lose weight and get more experienced, I'm finding sometimes I can actually do a few balanced seconds, but this is progress, but perfection.