The water that you use to steep your tea is just as important as the tea itself.
Start with fresh cold water from the tap, not hot water or water that has been previously boiled. Coldwater contains oxygen needed for flavor extraction. Hot water from the tap may pick up minerals and scale from your hot water heater which will negatively impact the taste of tea. Previously boiled water has already lost oxygen and will continue to lose oxygen every time it is reheated. If your tap water does not taste good, try filtering or use bottled water, because any unpleasant taste in your water will come through in the tea.