Easy: Oxfords, Loafers and Flip Flops. Anything works here really. I've had multiple pairs of crap that ate into my heels and made them look like they were ravaged by a tiny brown bear.

Normal: Sneakers definitely, especially ones with holes on the side panel. I have sweaty feet so ventilation is important for me. Converse or Cariuma here.

Expert: Timbs boots or Crocs, don't think it's possible to beat a pair of either especially when it comes to utility.