Short messages that work
For a close friend: Thinking of you and holding you close. I am here for anything you need. For a family member: We love you and we are with you. Remembering Dad with so much love.
For a coworker: Our thoughts are with you and your family. Take all the time you need. For a neighbor: We are so sorry for your loss. We are right next door if you need anything.
Using the person's name helps. Remembering Ruth and her laugh, says more than a general line. A specific memory, if you have one, is the most meaningful thing you can write. Sign with names the family will recognize, and add a last name if you are a coworker or old friend.