To dream that you are decorating something indicates you are trying to cover up imperfections or render something as clandestine to others. You do not wish for others to find out what may lay beneath the exterior of the object that you are decorating. At the same time, dreaming about decorating may reflect your desire to ignore or bury an issue at hand. You put layers and layers of decoration on top of it, hoping to avoid addressing the very heart of the issue. You rather deal with the superficial layers first and want to worry about the core of the problem later.
Alternatively, decorating in dreams can indicate that it a time of celebration and festivals. You are in preparation of honoring the holiday or a prominent day in your life by embellishing it with pretty ornaments and garnish.