Architectural Style of the home will impact the style of the hardware. Manufacturers produce sets that coordinate with each other and with the home.
Age of Occupants will have an effect upon the types of handles that offer ease of use. Levers are easier to grip for older and younger hands.
Weight and Height of the door will suggest the number of hinges and thickness of the hinges to effectively hold the door in the frame for accurate opening and closing.
Direction of Opening/Closing is important to understand, especially if using levers. The direction of the lever handle and the side of the door it will be installed on will have an impact upon functionality.
Security for interior rooms may be an issue for families with special requirements, such as home offices, expensive collections, wine rooms, etc. The use of the room requiring security will have an impact upon the type of security required.