"I am not the same, having seen the moon shine on the other side of the world" - Mary Anne Radmacher
If possible, include a free day in each destination you visit so you can relax and explore on your own. I always do this at the end of my trip, as I am more familiar with the area and I can revisit the places I liked the most.
Research first! Before you get to your next destination, find more about the country's culture, history, language and fun facts. This will make you fall in love with the places you visit and truly appreciate every second you spend there.
Always carry a portable battery charger for your cell phone or camera. If you love to take pictures like me, your cell phone battery won't last long. This is extremely important if you are having an afternoon at your leisure and need google maps to get back to your hotel.
When was the last time you did something for the first time? Be open to try new things while you travel. Hike, try new dishes, go to that chocolate workshop, visit a local community, practice yoga in the middle of the mountains, meet new people, etc.