This is what I came up with:
I did the layout in my Misti to figure out how I wanted this to look, this is a good way in my opinion to try things out before stamping.
And to get good ink coverage on your solid stamps, rub the surface with a white rubber eraser and remove any rubber flecks with your hand before you start stamping.
Simple Shapes XL
and a Misti - you could totally use acrylic blocks and a "manual" stamp positioner for this but the Misti does make it easier.
Here's a close up of the back of the card and the envelope, I like to make it the total package.