I did a little bit of masking on this card - stamp the image on the sticky part of a Post-It note, trim it just inside the edges of the stamped image, then place over the image you do not want to get ink on. Ink up another image and stamp on cardstock, keeping Post-It note in place. Once done stamping, remove the Post-It note and it will look like your masked image is in front of the one you just stamped!
I used masking on the two small tulips in Highland Heather and Pacific Point, towards the left of my card.