Whether you plan on "borrowing ideas" or plan on creating your own landscaping design, you should have at the very least a basic understanding of the principles of landscape design.
This doesn't mean that you have to apply every principle to every part of your plan. But just having an understanding of these principles will help you generate ideas and increase your creativity.
Great landscaping lies in the eyes of the its creator. So, while the principles of landscape design are great guidelines to follow, don't feel like they're the "have to rules" of landscaping. Abstract and creativity are allowed.
- Unity should be one of your main goals in your design. It may be better understood and applied as consistency and repetition. Repetition creates unity by repeating alike elements like plants, plant groups, or decor throughout the landscape. Consistency creates unity in the sense that some or all of the different elements of the landscape fit together to create a whole.
Unity can be achieved by the consistency of character of elements in the design. By character, I mean the height, size, texture, color schemes, etc. of different elements.
A good example would be in the use of landscaping rocks and accent boulders. If you've ever seen a landscape design that had one large white round boulder here and another large red square granite boulder there and so on, then you've seen that unity wasn't created by this particular element.
A simple way to create unity in your landscape is by creating themes. And one of the simplest ways to create themes is by using a little garden decor. Creating a theme garden is easier when it's related to something you're interested in or have a passion for.
If you're into butterflies for instance, you could create a theme using plants that attract butterflies as well as using statues, ornaments, and other decor that are related to butterflies.
Unity should be expressed through at least one element in your landscape and preferably more. Using elements to express a main idea through consistent style and a specific theme is what creates harmony.