Here are some tips for getting the best photos:
Turn on lights and open curtains to maximise light.
Ensure rooms look clean and tidy: make beds, hide personal possessions, put toilet seats down.
Remove any cars from the drive
Point the camera body at the brightest light source to ensure an even amount of light falls on each lense.
Light shared across both lenses
No visible lighting issues:
Light shining on one lens
You can see a drastic lighting change between the two sides of the photo: