Separate the jobs of the two hands
The long hand shows minutes and the short hand shows hours. Start with whole hours, when the minute hand points to twelve. Ask for just the hour first if reading both hands feels difficult.
A second hand can add confusion on a household clock. Begin with a two-hand diagram or toy clock.
The minute-hand number is not the minute total
When the minute hand points to three, it means fifteen minutes. Point from one onwards while counting five, ten, fifteen and twenty. Practise whole and half hours first if counting in fives is still difficult.
Each small tick is one minute; the five ticks between numbered positions make five minutes. Introduce one-minute intervals after the five-minute pattern feels familiar.
Read the hour it has passed, not the nearest number
At 3:45 the hour hand is close to four, but has not reached it. Describe it as travelling from three towards four and point to the gap between them.
At 7:50 use the same reasoning. Show the hour hand moving gradually from seven; it reaches eight only after sixty minutes have passed.
Draw the hands after checking an answer
Instead of simply replacing a wrong answer, draw the same time on an empty circle. Check that the hour hand also moves as the minutes increase.
If minutes are correct but hours are wrong, compare hour-hand positions rather than repeating every part of the activity. Choose by the times your child can read comfortably, not age alone.