Here's another easy, striking format for a card (any occasion) that yields a nice result. Pick two stamps. I love flowers, and this stamp is really cheerful. I took a bold color, folded it with a noticeable difference in bottom lengths (there is probably a special name for this style, and I have no idea what it is). Then I grabbed my white embossing powder.
I am a texture person, so I took my cute big daisy stamp and covered the whole front of the card and ten I stamped part of the stamp on the bottom margin inside the card as well.
I stamped and embossed the white card stock, too!
I intentionally made this photo large so you could see the detail.
I think you could really re-invent this concept with all sorts of stamps, really. Simple geometric shapes, woodgrain (for a masculine card)... lots of options. Have you done much with tone on tone embossing? I'd like to hear about it!