If you are sending me a card, and would like to receive a reply, tell me you want a response, and then write an address clearly so I can write back.
I would be excited to get:
retro style travel posters (on a postcard, not actual old card, but a new one with a reprint)
tea, coffee pictures
maps, old maps,
architecture, (structural, engineering, technical drawings too)
cards printed by Tushita, Nouvelle images, Graphique de France, Inkognito
Michael Sowa art
anything Quentin Blake, Sempé
antique botanical drawings of flowers or plants,
black and white photography
tidy and neat things
fountain pen pictures (if you have those Kaweco post cards, that would be great)
something technical or technical-looking (electrical schematics, diagram type illustrations)
nice postage stamps ( I appreciate it when someone puts thought into choosing stamps for me.)
This is just a list of wishes, if you don't have any it is ok to send any card, if you take the time to write a good message.
But please, no glitter. Save it for somebody else who loves sparkle.