Dr. Noir here! I really like these bits from Dr. Pepper's Places For Passion: The 75 Most Romantic Destinations In The World, And Why Every Couple Needs To Get Away.

You need the right setting to put you in the mood for romance. She says, "You'll be surprised how it all comes together when you add new scenery. A little atmosphere to get passion jump-started.
You need uninterrupted time together. For romance, you need time to talk, walk, and have a little fun together.
You need to wake up your brain. Sharing something new as a couple can be very sexy.
You'll feel more pride and gratitude. When you actually go to a place you dreamed of, you feel proud that you made it happen.