The palette
The bay is the largest mass on the sheet: give it an ink deep enough to hold the curve of the waterfront and the long line of the bridge across it. Green has real weight here too, because Balboa Park is a true surface and the canyons above it branch through the streets; choose a green that holds up over a large area without overpowering the water. The downtown blocks are small and tightly set, so a mid-tone street line keeps them distinct, with the darkest ink kept for the motorways that close them in.