Searches on the Internet for a specific item can result in massive savings.
Buying items second hand from other reefers on forums or from a local club will help considerably, even if the item is slightly damaged. DIY can soon sort these problems, for example a damaged cabinet or even the wrong finish that you don't like. Designing and building plays a real big part in this hobby and is a great way to gain achievement.
Swapping Equipment or Corals is a good way to get something you need or want, this works both ways. You never know what you might come across.
Buying coral frags and letting the frags grow into corals creates a real sense of achievement.
The next obvious option is fragging your corals and trading for other corals, equipment or livestock.
Using energy saving products like the new Led lighting from TMC can reduce energy consumption up to 50%. Many new products are on the way. I will be showing a keen interest in these products, I may even review them to help guide other reefers decisions.