Istanbul is one of those places where the obvious plan and the good plan are two different trips.

We mapped a 3-day Istanbul route ourselves, planned tight so nothing gets wasted, built to avoid the Hagia Sophia queue from day one.

This is the itinerary people wish they'd found before they booked, not after they got home. It's completely free to download, so the only real risk is not opening it before your trip's already planned.