Now when starting a new city, is your goal first to ensure it will grow, and then to work tiles to give you maxinum shield output and then back to the fastest possibly growth?
Because this is what I do:
I make a new city, and set it to either build a worker or temple. (normally 10 turns and 30 turns, respectivley)
I work the land to make sure it will have enough to make my city grow in 20 turns.
Then I work the land to make shields, so that I can make all the necessity buildings relativley quick (granary, barracks etc.)
Then I go back to growth so I can choose to use more tiles to work for me, faster.