I do! It's super fun, and probably saves me a bit of money considering how much cards can cost these days. It also means the recipient gets a completely unique, handmade card (unless I make multiples of the same design, but that's rare).
I mostly use pre-bought cards and then decorate them with scrapbook paper, stamps, and embellishments. I'd really like to get a die-cut machine someday and maybe try selling my cards online.
If you make your own cards, what kinds of things do you use?