A good question.
A local answer.

Keep enough time for the return from the gardens or summit, where service frequency may differ from central Brisbane.

Carry water, sun protection and an offline map, and check your return service before starting uphill.

If time is limited, enjoy one central garden well instead of spending most of the morning reaching a second.

Look for the shortest level route to the main lookout and confirm whether the viewing area has seats and accessible toilets.

Check the airport transfer's current schedule and keep a firm turnaround time; a river ride may take longer than a simple walk and meal.

Check current event listings for your dates. A local performance or market can make an evening more distinctive than another long drive.

Confirm which service is free or paid today; older forum references to routes and fares may no longer apply.

Ask the hotel whether its fee covers a 24-hour period, the overnight stay or a fixed entry-and-exit window.

Check the last train or bus for your exact date before deciding to leave the car behind.

Explore a food market or neighbourhood dining street and compare current menus before choosing a place.

Check restaurant kitchens near your hotel for that Sunday and reserve a realistic arrival time after airport transfer.

Build days around a playground, shaded park or riverfront walk, then add one short paid attraction if it suits your child.