Due to increased demands for energy and the current limitations of batteries, a future prospective technology are vibration energy harvesters that convert kinetic vibration energy into electrical energy. These energy harvesters have the potential to be used in powering small electronic devices such as measurement equipment in remote or hostile environments where batteries are not a viable option. Current limitations of vibration based energy harvesters is the total available power generated and the frequency at which they effectively collect ambient vibration sources for producing power; this paper aims to review the current techniques that are being employed to enhance the performance of these devices. These techniques have been categorised into amplification techniques, resonance tuning methods and introducing nonlinear oscillations. Before this technology can be used effectively in applications enhancing the performance of ambient vibration energy harvesters needs to be addressed.