Those are so fun! I think they'd look great with jeans and a t-shirt!
I've used this tutorial to make shoes for my 11 month old:http://www.tackyliving.com/article.php?id=121
The only mods that I've made are to put the casing inside the shoe and I use a clover 1/2" bias tape maker to do the casing. I don't have a serger and the way the tutorial does it is a huge pita!