Originally Posted by Cat Herder:
Free printable shoe size chart from Gap may help. 
We are all so different. 
I don't allow shoes with laces for kids who can't tie their own shoes. I love crocs for summer/water play. I prefer velcro sneakers. I do not allow open toe shoes year round. If they don't fit, I send them home in loaners with their other pair in a bag for replacement.
I don’t have a specific policy when it comes to shoes as I haven’t run across any problems yet. One little girl wore crocs this summer. I loved it, they were easy to slip on/off, she could run and play in them fine without them falling off and she could get them on herself really fast and then wanted to help her friends with theirs.
I’ve found these are my favorite type of shoes of all the shoes my kiddos have worn.