I learned this technique at a local stamp store about 2 years ago. I absolutely love it and it is one of my favorite techniques! It is also a great way to make use of all those 1/2 inch strips of paper you end up with when making layered backgrounds.
Secure strips of 3 different coordinating papers with removable tape onto scrap paper and stamp randomly over the top.
Remove the strips and alternate them vertically and horizontally on sticky back paper.
Use another stamp and metallic ink to stamp a few images over the top.
This looks hard but it is SO easy and you can whip out some really nice cards in no time at all!