I suggest when in Milan to spend an evening in the "Navigli area", especially during the summer
You'll find here lots of cozy outside restaurants, pubs, bars, one close to the other. Also, the two main streets are full of cheap handcraft merchandise sold by Indian and African people
This area is in an area called Porta Ticinese
Take the Green line to Porta Genova or tran nr 3 or 15 from Duomo
The Naviglio district at night is wonderful- sitting in an outdoor cafe or restaurant, soaking in the sounds, sights and smells. Everyone is out, everyone is gorgeous, lights shimmer along the canal...and the mosquitoes are out in full force.
Either bring bug spray or wear light (breathable) cotton long pants and shirts if you're going to sit outside. A wonderful dinner, a good bottle of wine, a creamy gelato or a moonlit stroll can be ruined by the mosquitoes that love this district as much as the locals and tourists do.
Favorite thing: Walk along the Navigli, have a drink at Corso Como 10, happy hour food and half priced drinks at Fresko bar in via Bramante, see the Duomo, la Galleria and that neighbourhood, walk up and down via Monte Napoleone and notice that you ain't missing anything. HAve a great time.
Walk in the center (avoi buses or trams and most of all cars)
Visit the Universities. both Università statale (in festa del perdono street) and Università Cattolica (largo Gemelli) are beautiful places with a lot of history in their walls.
Go to the Navigli area (again no car)
Fondest memory: I miss my home
I was bored last weekend August 2001, so drove from London to Milan via France, & Switzerland, then back via Luxembourg in 3 days! It's great to see nothing's changed. Bar Magenta on Corso Magenta is still thriving - the restaurants along the canal near Porto Ticinese which serve G & T as 80 % Gin, 20 % Tonic are just as good, as is the all-night street market, on which you can buy incense, jewellery, t-shirts, and central heating boilers (I kid you not - I have photos!) while listening to live Italian ragtime bands in the restaurants.
Info for the mad drivers among you, I sat at around 115 mph for most of the distance, and according to the car's computer, averaged 75 mph for the trip, including driving breaks in cities.