Acknowledge the loss. Please accept my deepest condolences for you and your family's loss.I am thinking of you and sending my love. Keep the letter as brief and as short as possible. If you must say something, a very brief and positive personal statement is probably good. I know I can't do anything to make you feel better, but please know I'm sharing in your grief. Sandy was an incredible friend, and we'll all miss her so much. An appropriate signoff could be something like "with sympathy", "with caring thoughts" or "our sincere sympathy". We share our sadness, joy, laughter, and memories. I send all of my heartfelt condolences.