Fortunately for the water-feature-builder, the artistic urge is the driving motivation when starting out: everyone wants to pour their imagination and the love of nature, water, plants and rocks, into the project and make it intensely personal. The point is not to forget our strong urge to make Beauty; because it can quickly be submerged under “reality-considerations” like material selection; site and budget constraints, waterproofing, hydrodynamics, filtration and so forth.
So to begin, take some time to dream and imagine. Gather together any and all the pictures you have ever seen of water features that you have liked, and any notes you might have made over time, about what you want. Sometimes you know “just where you want to put the water feature”, sometimes you are open to ideas. Bring it all together no matter whether it looks jumbled or not
And sketch, even if not clever or to scale. Start with exactly what you want, don’t focus on the limitations, there is time for that later. In this way you will bring all your imaginations into stronger focus. Obviously site restrictions must be considered, but don’t get bogged down in details.
Apart from the fact that this dreaming process is fun, like creative “free-association” it brings to the fore things like the Mood that you want your water feature to have. By doing this dreaming, you will get a stronger feeling of what you want: a placid mood, or a boisterous full-of-splash mood, or a water tricking or gliding mood: somber, or jovial, or a mixture of all of them, but -more accurately- in what order and what prominence.