natural sea sponge pieces (found in the paint section of Wal-mart or your favorite home center)
your choice of three dye ink pads (two will work, but three is best)in light medium and dark colors
Wet sea sponges with water. Ring them out well. Place in doubled paper towel and squeeze excess water out. Sponge needs to be moistened to make pliable, but excessive water will blur sponging and will result in a more watercolor effect on paper and could be harmful to your ink pads.
Mask off area that will NOT be sponged using scrap paper and blue painter's tape.
Wearing gloves, dab sponge piece onto lightest ink pad. Then apply to the cardstock in random twisting motion. Re-ink sponge as necessary.
When, when desired effect of this layer is achieved, move on to medium color ink and a new sponge and repeat previous process of dabbing until desired effect is achieved.
Finally, using darkest ink, apply with the same process until final overall effect is achieved.
Wash sponges with water and mild soap and rinse well. Ring again in paper towel to assure all ink is removed. There will be staining on the sponges, but if no ink transfers to the paper towel, they are good to use again.
Allow to dry completely.