Pick a few anchors
Choose the experiences you would be genuinely disappointed to miss. Book those with enough space around them. A morning walking tour, for example, does not need to compete with three other timed activities.
Give yourself permission to linger
An unplanned afternoon could become another hour in a museum, a conversation over coffee or a return to a street you liked. It can also become a rest. None of those outcomes means the day was wasted.
Use local knowledge without outsourcing your interests
Ask a guide what they would suggest for someone with your preferences and energy level. Their answer may be more useful than a generic list, but you can still choose differently. The point is to find options, not to turn a holiday into an assignment.
Keep essential logistics planned
Unplanned does not mean ignoring transport, your accommodation, entry requirements or safety. Know how you will get back and keep current official information available. Leave flexibility inside a plan that covers the essentials.
Remember what you actually enjoyed
At the end of the day, write down one detail you want to keep. A sound, a conversation or a small discovery may tell a richer story than a long list of places visited.