This started as an experiment with some plastic shaders in Blender.
I have always been slight frustrated by my shaders as they looked slightly wrong and I didn’t know why.
I read some comments from Logan Ball about setting up shaders in Cycles and was intrigued to see if it worked.
You can see more on his google page https://plus.google.com/+MachinaArts2015/posts
Basically he suggested always having a glossy shader mixed with another shader and to use a mix value based on the index of refraction of the material you want to emulate. No more using random mix factors on materials!
If you are a blender cycles user the tip for getting this plastic look is using a RGB curve to mix glossy and diffuse shaders. There is an image attached below.
Now these shaders are not perfect, there are more accurate ways to do this, but for a quick and dirty set up it works well.
A lot of a materials visual qualities depend on the reflections, you could use a HDRI image for the sky or some colour ramps as I did here. Also add some random off screen meshes and lights to reflect back into your scene. A wide angle lens on the camera with some mild DOF also helps.
After setting you curves for various materials ( experiment! ) you can adjust glossiness values and colours. Use some mild textures with a bump map to mix into the normal socket of the gloss shader to break up the sheen.
I also mixed in a little sss and translucency on some of the materials, but found it made only a small difference, maybe it depends on the lighting, if it was coming from behind you would notice it more.
My daughter has hundreds of plastic toys left lying around the house so there was tons of inspiration. Also have put in a few of my own designs. Some are from a project a few years ago where i was commissioned to produce around 30 vinyl toys. The commissioner dropped out right at the end and I never knew why ( though he did pay most of the money! )