[Your Name, & Address here]
[Recipient Name & address here]
This is just to let you know that you will be in my thoughts all the time while you travel through – [State locations here].
I am sure you will have a great time, and I really envy you as I am not with you. Maybe we go together on a vacation in the future.
I advice you to travel safely and take beautiful pictures to show me.
I am waiting to know about your adventurous experiences when you return from the trip.