We explore optimal ways of communicating (with a power constraint) over multiple antenna communication systems by managing spatial power distribution. We find that Mutual Coupling (MC), the interaction between antenna elements of an array, determines the power efficient schemes. MC at the transmit array affects the amount of power drawn from the supply, and this power can be calculated by integrating the power radiated by the array in all directions. In this thesis, we focus on two problems, both of them assuming knowledge of perfect channel state information: (a) Finding the Signal to Noise Ratio maximizing scheme for Multiple Input Single Output channels, and (b) Determining the capacity achieving scheme for Multiple Input Multiple Output channels. Our solutions, Coupling Optimized BeamForming and Coupling Optimized WaterFilling outperform beamforming and waterfilling respectively, and the extent to which they do better depends on the strength of MC.