Postcards require short language and a strong sense of blessing. Unlike letters from home, they are long and rich in content.

As paper is limited, writing postcards should be short and clear. And the content doesn't involve privacy or something you don't want others to know.

If it's a postcard of you traveling outside, you'd better make it clear where it is and whether it's safe now. If possible, tell your family when you will come back. Something like that