We painted the ceilings white with dark brown trim to lighten it up inside. Natural sunlight was lacking inside the cabin which kept it nice and cool in the summer. Cleaning the layers and layers of scum off the windows also helped to bring light in. We ran the entire cabin off of two outlets. We bought only low voltage light bulbs and we had a mini fridge and little hot water heating kettle. It was comfortable to sleep in there from March till the end of November when the first frost came.
Jameson built us this greywater sink. We would cart 5 gallon buckets down from the main house. That white cooler acted as our sink and the water would drain into another 5 gallon bucket under the sink. We used all natural soaps and had a spot outside where we would toss the used water so it could filter through the earth. The system worked quite well.