technique for painting a milk can to make it look old and rusty

A few months ago, I shared this old black milk can and asked your advice about what the heck to do with it. This milk can was a gi.

I like the "enamel ware" look of this can.  Maybe do it in actual enamel ware colors.

Re-purposing an Antique Milk Can

Old Milk Can Makeover {Tutorial}

Old Milk Can Makeover (Tutorial