Disclaimer: I have never really done a cooking tutorial, so I hope this makes sense. Also, you should be forewarned that I had NO idea the grainy background stamp lines were so close. I had to improvise, but I think you'll get the idea.
First, stamp the image on the backside of a piece of wax paper. Then grease an 8X8 glass pan and put the wax paper inside. I place a paper towel underneath the plate so I can see my stamped image better.
Melt white chocolate and put in a plastic bag with the smallest tip you have. I used #2, but it still needed to be smaller. This is my tip for filling my bag. I place it in a cup so I can use both hands with ease.