It is important to site your aquarium on a level base. Make sure it is placed away from direct sunlight to reduce algae. An aquarium must not be placed near any household heating appliances as this could cause wide fluctuations in temperature (a difference of three degrees Celsius over a short space of time can be detrimental to the inhabitants of your aquarium).
Aquarium design is not just about aesthetics, it is about providing the appropriate surroundings and water chemistry for your fish. In order to provide your chosen fish with a more comfortable natural environment, it is best to do some research into the natural surroundings and requirements of your chosen fish, before setting up your aquarium, as once it is set up it is not as easy to change things around.