Every home improvement situation is different. Still, there are some general points that apply to most projects.
Some General Points
When all the woodwork in a house is the same color (cream, white, and off-white work easily), spaces tend to visually “flow smoothly” even if the walls of rooms are different colors. Make sure you don’t break this rule.
The colors of all rooms, which can be seen at the same time, should look good together. Let’s take a typical center hall floor plan for a modern two-story house. The living room and dining room are to the right and left of the entrance. The foyer goes straight back to the family room, breakfast area, and kitchen across the back of the house. There is probably a deck opening off that area. Some part of all those areas can be seen from each room, and the foyer walls continue upstairs to a hall from which each bedroom is visible.
To continue our example with cream woodwork, the foyer and halls might be painted a pearl gray, light tan, soft gold, or deeper cream. The woodwork is probably a gloss or semi-gloss and the walls and ceiling a flat paint. Since ceilings reflect light down on people, they're usually best in cream or off-white. I once saw a dining room with an indirectly lit octagonal tray ceiling painted to look like creamy clouds in a peachy sunset sky that made every dinner guest look like he or she had a perfect complexion. It was wonderful.
The living room opening off our foyer might be a solid color (maybe sage green or deeper tan) or it might look very handsome with a vertically striped wall paper (cream and gray, cream and green, or cream and tan are good possibilities). The dining room is apt to have a chair rail. A darker color could look good below the chair rail (again sage green, gray, gold or tan would work) with a lighter tint of the same color above. If a solid color were chosen for the living room, the dining room could handle a deep red below the chair rail and a cream paper with a narrow red stripe above it. Lots of crystal and mirrors would look terrific in a room like that.