I bought some rolls of double sided sticky stuff a couple of years ago, you stick up the tape on suitable surfaces (like the stair wall) and press the cards onto it.
maybe buy one of those card holders then, there are some lovely ones out there, my problem is that if you have a few left, where do you put them?........
have seen some lovely freestanding ones 4get, they have rings to hold the cards, but won't hold many!.........maybe look at them...depending on how many cards you have, this may be the answer, you can use them year after year!...........
I use some gold or silver ribbon - the narrow type that you wrap presents with - and fasten it round the door from top to bottom ie under the door and back up to the top and fasten it on top of the door with a large drawing pin. This can't be seen a its too high up to be noticed. I then use a small stapler and staple the backs of the cards to the ribbon. This way they can still be opened and read. I then attach a few matching/contrasting sticky bows to the ribbon that is on the other side of the door for a bit of fun. Hope this make sense. It is quite effective and holds a good number of cards. There are no marks or holes left anywhere except on the thin strip at the top of your doors which you will never normally see - unless your name is Peter Crouch! Leaves all your other surfaces card free.