What works well with children, what tends to make the day harder and how to keep the pace realistic.
Keep transitions short
Walking by the lake, a boat and one clear attraction usually work better than trying to reproduce an adult sightseeing checklist.
Use food and shade as part of the plan
Summer heat and waiting time matter more with children. Build in stops before everyone needs them.
Choose one memorable activity
A boat, castle, easy lake day or short day trip can be enough. The goal is a good family day, not maximum attraction coverage.