I have come up with this draft itinerary for my planned trip to Europe from November to December (leaving before Christmas). As a background, I have already spent some time before in Paris, Rome, Florence, and Hamburg, hence, the tentative plans of doing day trips outside of these cities.
Day 1 - Athens to Paris - Taking the Plane
Day 2 - Paris
Day 3 - Paris - Day trip to Chartres/Versailles (Tentative)
Day 4 - Paris - Day trip to Mont St. Michel (Tentative)
Day 5 - Paris
Day 6 - Paris to Brussels to Amsterdam - One day in Brussells. Taking the train
Day 7 - Amsterdam
Day 8 - Amsterdam
Day 9 - Amsterdam to Hamburg - Taking the plane
Day 10 - Hamburg - Visiting my sister and will have some sort of a rest
Day 11 - Hamburg
Day 12 - Hamburg to Lisbon - Taking the plane
Day 13 - Lisbon
Day 14 - Lisbon
Day 15 - Lisbon to Madrid - Taking the plane
Day 16 - Madrid
Day 17 - Madrid - Day trip to Seville (Tentative)
Day 18 - Madrid
Day 19 - Madrid to Milan - Taking the plane
Day 20 - Milan
Day 21 - Milan
Day 22 - Milan to Parma - Overnight at Parma
Day 23 - Parma to Florence
Day 24 - Florence
Day 25 - Florence - Day trip to Lucca(Tentative)
Day 26 - Florence - Day Trip to Siena(Tentative)
Day 27 - Florence to Rome
Day 28 - Rome
Day 29 - Rome
Day 30 - Rome to Athens - Taking the plane
Day 31 - Athens
I'm still trying to refine it and would be a great help if you could share your opinion/provide comments about the itinerary. Thank you.