The best way to write a sympathy card is to be genuine and simply say what you feel -thus, you should send your condolences as soon as you hear the news of the death. The following guidelines are for those who may be at a loss for words during the difficult time following a death.
Use personal stationery and a pen with blue or black ink.
Address the letter to the deceased's closest relative, such as the widow or eldest child, if you knew the deceased well but did not know the family well. If you did not know the deceased, write to the relative with whom you are acquainted and express your wish to give comfort, even if he or she is not the closest relative.
Express sympathy for the family and acknowledge their loss: "Please accept my sympathy for the terrible loss of your father."
Include a personal memory and/or acknowledge the character and accomplishments of the deceased. If you did not know the deceased, you can simply say, "It must have been wonderful to have him (or her) in your life."
Offer support and assistance in any way needed if you know the person to whom you are writing.
Avoid dwelling on the details of the death. Avoid euphemisms or dramatic conclusions such as "It's all for the best" or "You have lost your wife," which may seem to skirt the issue of the death or the suffering of the bereaved.