For my paper, I like doing designs like these;
(This is one of my favorites for smaller cards/paper.)
Envelopes are fun to decorate, also. I will usually do something on the front, and something on the back flap.
I read about this in a really neat book, "Training Our Daughters to be Keepers at Home" by Mrs. Craig (Ann) Ward: You take scalloped scissors to cut out a card, and then you take a needle and a piece of Styrofoam (place the card front on the Styrofoam), and pierce the card front for a neat design. I thought that was so neat!!! I haven't tried it yet, but I will!
I love making cards, too, but I don't have as much to say about them (I make way less of them, even though I would love to make more than I do.). But if you are just sending a little card, about 4x3 inches, a dogwood centered on it is both gorgeous and easy. And two or three coordinating papers can make cute designs. I like to save lace, tatting thread, ribbons, and lace from my crafting to use on cards (and little tatted items are great on them, too!). I use buttons at times, also. Scrapbook paper is great to use for cards so that they have an attractive background.
Dried flowers are another thing that I use all the time. I LOVE drying flowers :)! There are many ways to dry the flowers and then use them, but the pressed version pictured above is my favorite! Anyway, I just thought I would share a bit about that, as it is something I enjoy. But for something that would be more helpful... well, this post by Miss Tammy was good :).