Head height for interior shots
As you look through the viewfinder and tilt the camera up and down from the ceiling to the floor, watch what happens to the vertical elements of the picture. You will notice when looking into the lower corner of a room the perspective in the verticals becomes convergent. This means they get wider as they get further away. The opposite can be seen if you look up to the ceiling through the viewfinder. Both these convergent or divergent verticals should be avoided. To ensure that the verticals stay vertical, try and keep the camera completely horizontal. If your eye is 150cm off the floor and your camera is at the height of your eye then you should be pointing your camera at a point on the wall at the same height of 150cm.
Don’t be afraid to shoot portraits as well as landscapes – just because most rooms are landscape in proportion, doesn’t mean the photographer can only shoot that way. Often portrait photographs are more interesting.
Resist the temptation to stand on a chair in the corner of a room unless you want the image to look like footage from a security camera. Most interior photographers shoot around head height or just above ground level which can give a different feel to an image.
~Doug Jackson from his article Photographing Interiors