Work backwards from departure
Start with when you need to be at your departure point, using the guidance for your actual journey. Then allow time for the route, collecting luggage and any changes of transport. What remains is your real free time. Plan within that space rather than treating the day as completely open.
Sort out your bags the evening before
Confirm checkout time and ask whether your accommodation can store luggage if you need it. Check collection hours and any charge rather than assuming storage is included. Pack most of your belongings before going to sleep, leaving the things you need in the morning easy to reach.
Choose one nearby pleasure
Return to a café you liked, take a short walk or sit somewhere with a view. Familiar places can be a lovely way to close a trip. Avoid a distant excursion that makes the rest of the day depend on everything running perfectly. Keep your final plan easy to shorten or skip.
Bring the useful details home
While the trip is fresh in your mind, note the places you enjoyed and anything you would do differently. Save the name of that small restaurant or the room detail that made your stay comfortable. Then put the planning away. You do not need to organise your next escape before this one is over.