I am Russian-native currently residing in Munich: https://youtu.be/nIF_iPCKKn0
PLEASE make the card worth the postage (it's fun!) & write me a few lines. If your really don't know what to write, just go with a random fact about what's on the card
Alternatively, tell me a story:
What inspired you today? What makes you really happy?
You may get inspiration from the cards I like:
ARE YOU FROM THE USA?
I LOVE anythings USA: touristic cards, Route 66, Star-spangled banner, etc.
THANK YOU FOR YOUR POSTCARD