Parents of soldiers can modify this military goodbye letter for their children who are deployed.
Dear {Recipient},
Long gone are the days when I could tell you to buckle your seatbelt, wear a raincoat or remember your lunch. You've turned into a wonderful, responsible adult and I could not be prouder of your accomplishments.
That being said, I'd like to remind you to please, please be careful. You're going to a place I've never even seen, and that makes me worry about you. I know that you are going to put your skills and education to good use and to help protect the people you love. I find that incredibly inspiring and admirable.
However, you are my {relation} and I am going to love you and miss you like crazy from afar, so please watch out for danger and keep yourself safe. I know you'll be busy, but I will write you letters and I hope to hear from you when you can find the time.
We all love you and we already can't wait until you come back home.
Love,
{Sender}