Nothing fancy or too complex, but they work! I found the cards and envelops at Hollo's for CHEAP. When we bought card stock for our wedding invites it was $1 a pound. Granted, that was 5 years ago, but this place is a scrapbooker's/cardmaker's dream. Definitely worth the trip out there to stock up every now and again.
This year I used some old cards to make ornaments. I got the idea from a women's Christmas gathering we had for church last year, only we used scrapbook paper. So I found a bucket of cookie cutters (at none other than the famous, incredible, never-know-what-you're-gonna-find, Aldi). Then I sorted through some old Christmas cards and traced whatever cutter looked best on the front of the card. Using clear glue, I outlined the cutter with the glue and stuck on the cut-out shape. I did leave just a little cut in the top of the shape for room to stick the ribbon or string through. And here's what I got: