Hop aboard the free trams that run every 10-20 minutes, 8:30 am-6 pm daily, with extended summer hours.
Wear comfortable shoes—you'll end up walking more than you might expect. Bring a sweater or light jacket for the evening drop in temperature.
Don't be afraid to wander off the main drag. Discovering a hidden space of your own is one of the highlights of a trip to Balboa.
Balboa Park is a good bet for the odd rainy day—the museums are nice and dry, and many of the park's buildings are connected by covered walkways.
Make reservations for the Prado restaurant; it's popular with both visitors and locals alike.
If you aren't receiving the discount, consider avoiding participating museums on Free Tuesdays, as they can become overcrowded.
Don't overlook the 6th Avenue side of the park, between the Marston House and the Cabrillo Bridge. There are several pathways and open fields that make for a quiet escape.