My first polymer clay food experience was a class with Angie Scarr at a Guild Show many years ago, and it was a revelation. I have since taken some of my own adventures in making 1/12 scale food with polymer clay and the tips I learned with Angie, and some I discovered on my own, have helped to ensure successful outcomes.
The most obvious tip, yet one people still ignore, is direct observation, work from life whenever possible. If you can’t work with the original next to you, the next best is accurate photographs. To make some black and white cookies, I bought one and photographed it, placing some thread in the photo for a color reference to work from later. The best miniatures are finished accurately on the back as well so make sure to take reference photos there as well.
The cookie clay was rolled in thin sheets with a pasta machine (pasta machines are invaluable tools for working with clay-it makes them strictly off limits for future food use, but it makes conditioning clay and mixing colors much faster and rolls out perfectly uniform sheets), and cut out using a piece of drinking straw or other small round cutter. I used a piece of plastic drinking straw to gently roll the edges of the cookie to shape. The straw, having some give to it, made a gentler shape than a harder edged tool did.
It was a second class, this time at Guild School with Betsy Niederer, that taught me the advantages of artist’s pastels. Take your original inspiration to the art supply store to pick out the correct colors, then use a paintbrush to transfer color onto unbaked (also baked) clay to add a just baked appearance. Again, observe where the color is the darkest and lightest and follow that pattern on your miniatures.
Bake the shaped and colored cookies on parchment paper to prevent the shininess that occurs when baking on foil or metal sheets. The cookies are frosted with icing made from stirring liquid polymer clay into the regular polymer clay and it takes a while to master. Mix up and soften a small amount of clay to the color desired and break it into small pieces. With a popsicle stick or other mixing tool, work the liquid into the solid. There is no magic formula for how much liquid to add, you want it to be smooth and spreadable. Looking at the original, you will see that the frosting is pretty flat and even, so that is what you are aiming for. Trial and error is the only way to get there so use a few of your less attractive cookies to try out your mixes and your frosting process, bake them and make changes if necessary to get the desired effect.
And, next time you are shopping for miniature food, see if you can tell who seems to be working from original reference materials, and who may be working from memory.