Dear Adam,
You are a luchy man because you have two very good things to create a confortable office : grate space and a couple of windows.
Is very important don't sit with your back to the door. You could put your armchair in front of the wall, looking at the windows and doors.
Avoid to fill the office with an incredible amount of furniture.
If you have lots of books and papers it coud be good to have cupboards in the same colour of the wall, then they are harmony and the people and yourself will have a relaxed view and the energy will flow freely in your office.
To take care of the light is another advice.
In the room were the people wait is good the conection outside. In your offfice , this isn't possible , then you must put some pictures about mountains or nature.
I hope my simple advices are usefull for you.
Sincerely,
Lourdes