Low-Flow Shower Heads
Fitting a low-flow shower head may reduce hot water use during a shower by as much as 40%, which of course saves the energy that is used to heat the water. Water heating is the largest part of most households energy use.

Temperature
Check that the temperature of your hot water is about 60°C. If it is more than that it could be a burn hazard as well as wasting electricity. Adjust the thermostat to suit.

Cylinder Insulation

Good savings are available by paying just a little attention to your home hot water cylinder. Up to a third of the energy used to heat water can be wasted through poor insulation. While new cylinders usually have excellent insulation, older models will benefit from wrapping.

In all cases your plumber can provide additional advice and service.