First thumbnail drawings

The scenes I have chosen from the extracts are:
1 - Volcanic cave
2 - Mushroom forest
3 - Sea scape

I started sketching these beginning thumbnails to start thinking about what I want in my concepts, the scale of the elements and lighting. From this selection I feel one or two ideas have potiential but it is far from how I want to envision them so I will refer more closely to the research I have begun gathering to generate further ideas.