Dear (friend's name),
I hope this card finds you well and that you are enjoying the holiday season. I wanted to take a moment to let you know how much I appreciate you and our friendship.
It's been a challenging year, but you have always been a source of support and comfort. Your kindness and generosity have touched my life in more ways than you know.
As we approach the end of the year, I'm filled with gratitude for the memories we've made together and the hope of new beginnings to come. Let's make this Christmas one to remember!
With love and best wishes, (your name)