very good 8bstudio.
some crits tho:
- as you already mentioned, the sugar material. also the edges of your sugar cubes are too sharp - bevel them.
- are the chinese letters meshes? if yes, use textures instead and use a blurred bumpmap - will give good results i think.
- the wood-material is really good i think.
- the "walls" of your cup are too thick imo.
- you may model the meniscus of the coffee surface, like
this
- as already mentioned, overlall brightness and contrast (new indigotonemapper will help

)
- keep it up!
