Shaving cream and food color backgrounds

I hope everyone is having a good week.

 I had someone ask how I do the shaving cream and food coloring backgrounds I use sometimes, so I hope this instruction will be understandable. First I get a glass plate and spray about 1/2 inch layer of shaving cream on the plate, then take a palette knife and smooth out the cream. Next I take two or three colors of food covering and squirt several drops randomly on the shaving cream. Then use a tooth pick and swirl like you would do on a marble cake. Don't stir or swirl to much or your cream will turn gray. When you have your color the way you want it lay your card stock, or paper front side down on the top of the cream lightly pushing to capture the design. After a few seconds remove the paper, lay on newspaper or some kind of covering on your work area. Take a firm card like an old credit card and scrape excess shaving cream off of the paper. Let dry which is very quick and you are ready to use. The shaving cream left over can be used again, I usually get four different backgrounds before the color starts muddling and turning gray/greenish. I think this is an easy process, and hope I explained in a simple enough manner. If you have additional questions post them on comments and I will get back with you.
Are there any other artist whom would like to share a technique with us, please do under comments. This is how I am learning is with other sharing idea, techniques, etc.
I am working on the challenge sponsored on Craft Barn with this weeks challenge being the letter R, if you have never participated check it out. Have a great and creative week; let us know what you are involved in.