Sending postcards for some may seem a bit old fashioned, but for most of us it’s one of the cutest ways to show affection 
(especially in the summer holiday season
).
When writing a postcard you might want to include:
a date on the top-left corner on the back of the postcard;
a greeting phrase (leaving some room for your message below): Dear, (name)/Hello/Hi/Hey, (name)!
a special memory (but be conscious of how little room you have);
something touching: I’ve been thinking about you./I wish you were here with me!
regards for other people who also might read the card: say hello to the kids!
mutual future plans „I’ll see you soon,” or, „I can’t wait to see you!”
don’t forget to sign your name on the bottom left of the postcard.
Do not write about anything too personal as you’ll be exposed!