Milan is so close to Vigevano - the city of the shoes !
Bestetti - http://www.frecciabestetti.com/
Moreschi - http://www.moreschi.it/home.htm?lingua=eng - Factory outlet very very very cheap !
Gravati - http://www.gravati.it/inglese/home1.htm
and also so close to Parabiago where you can find the factory outlet of Fratelli Rossetti - http://www.fratellirossetti.com/en/Link/
If you have time, after all the shopping, just try to go to one of the...