Birthday cards can convey humour, tender sentiments and happy wishes for another year of life. With a little care, you can add your own message to the printed card that will assure the recipient that you are thinking of her on her special day.
If the message of the card conveys tender thoughtfulness, continue that feeling through your handwritten thoughts to the person. If the card tends toward the humorous, personalise the joke by adding your own comments.
It's important to add more than just your name, even if the printed message is lengthy and conveys exactly what you desire to say. Add a wish for a happy birthday and assure the recipient that you are thinking of him. Even if your message isn't perfect, at least it won't feel insincere and generic, as it might if you didn't add anything to the printed message at all.
Certain types of birthday cards require caution when adding your own message. For example, if you send the card a little late, apologise sincerely for the tardiness. If your card carries a humorous message, consider whether the person will appreciate a joke you add, especially if the joke regards ageing.