Just like building your own home. It’s all about location.
The ideal position for any pond is an area that gets good sun and a little shade. Six hours of light will be sufficient for plants and fish. If your pond is in full sunlight you should consider the use of a shade sail or you can install a Ultra Violet Clarifier (UVC), like the Oase Vitronic or the Oase Bitron which will break down and kill green water algae. You may be able to create shade with careful consideration when planting out your pond and surrounding garden.
Ground levels are a factor when considering where to place your pond. Level ground will make it easier to build but for those areas that are not, you can build up your levels using excess soil that you remove from the pond site.