I've always had problems getting shoes that fit. I find Sperry top-siders, or billfish are usally comfortable, but with so much production going to China, attention to sizing is questionable. I have used these shoe trees and they worked well. Make the shoe a little wet, and apply pressure with the tool. Add additional pressure, but not to the point to dammage the tool ( it is not the best quality construction) and leave them expanded for several days, perhaps a week. Sometimes adding additional tension during this time is good.  Do not forget to use the little plastic toe pieces to get the best custom fit.