Transitioning smoothly between verses and the chorus in "A Thousand Years" can be challenging. Start by practicing each section separately to get comfortable with the chords and melody. For seamless transitions, slow down and focus on the hand movements necessary to shift between chords.
Consider using pedal techniques to bridge these transitions—just make sure not to over-pedal, as this might muddy the sound. For finger placements, try using a finger substitution technique where you replace one finger with another while holding a note, allowing you to prepare for the next chord without breaking the flow.
Emotionally, "A Thousand Years" benefits from dynamic control. Practice playing with variations in volume to emphasize the song’s emotional peaks. Look for sheet music that includes dynamic markings, or consider listening to various piano covers and tutorials on platforms like YouTube for additional interpretational insights.
Sheet music by Musicnotes or similar sites often offers officially licensed arrangements that may come with performance notes. Keep practicing, and over time, your expression and transitions will improve. Good luck!