First, whether you work at home or away, get a feel for your work area. Try the furniture in different positions and see which ones accomplish the effect you're after. One of the most important recommendations is to sit facing the door, either directly, or by using mirrors, so you can see who is approaching. Another suggestion is to have an entry bell, so that you immediately know when someone is entering the building or office, allowing you to focus better on your work. Have something living, like a plant or a goldfish on your desk.
Water is equated with wealth, fish with money.
Red is considered lucky. Purple brings wealth, pink is a partnership color, grey fosters helpfulness. A door painted green is said to increase income. Avoid octagonally shaped offices. Their energy is too strong and should be reserved for religious spaces.