This tutorial will show you how to get a plastic effect to your image. First, open a new document like usual, and paste the image in. I have choosen this image:

-Now go to Filter > Filter Gallery

-Next, go to the section "Artistic" and click on Plastic Wrap.

Now you should see what is shown below, play around with the green/while arrows until you are happy with your effect. the detail helps you choose how much of the plasic you want, the highlight strength makes your image lighter and darker, and the Smoothness, smooths the plastic.

This is what I ended up with. Hope this tutorial helps!