i am still busy writing a userguide on conversion
Here is a portion of it:
Diffuse Material:
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Transmission is a color or texture which will be mixed with the diffuse color or texture. It determines how much light is passed through the material. This node is used for material like lampshades or scattering.
In the picture below I placed a ball with an emitter material inside lamp. The lampshade had its transmission channel set to white. For best result I increases the emitter samples to 1000.
I have not finished with SSS, that will be a separate section, but it boils down to this:
Diffuse material, use your textures as normal, add a reddish color or texture in Transmission. then in Medium add Scatter. Set Density to a low value, Scattering to 1 or white. Now tweak the density value.
It is a complex subject, and doing it like this will likely not be the result you want. Redspec shaders does it quite nicely and it is a complicated shader. In the guide I use a more simple approach. Basically it is mixing A glossy with your normal materials with the diffuse scatter material.