I suppose a north window is important. For me it's important not to have to work in direct sunlight. I can work day and night and I do.
Art history is very important to me. First I can look to see what others have done, and they simultaneously give me permission to experiment around.
There is nothing like a blank canvas staring back at you, daring you to make the first commitment. After the first mark on the surface there is no holding back.