I tend to look for the style we have from the past but as others mention in the next size up. Some of the online stores have sizing charts you can print out and measure your foot against. We did our most recent sneaker 'refresh' at Nordstrom Rack. We've also done 6pm, the rack equivalent of zappos. We usually buy enough from either to get free shipping and while neither has free returns but I figured the $8 + discount still beats trying to get them someplace (and we don't have any malls around, so it's pretty hard to try kids shoes on in person even in a normal year)
~ Dawn
Our little monkey (4/2011) & his early holiday present 12/12