It’s simple: everything that you look for in a painting or a piece of art you also want to look for in your garden landscaping. For example, how does the color work? You might want to explore some color theories to further broaden your horizons on how colors work. What flowers and plants should you have in your garden to get the colors to work for you?
Perhaps one of the easiest aspects of gardening landscaping to notice is the texture of the garden. Really, how do you want the texture of the garden to look? Large and leafy, small and plain, flowery, animal statues here, do you want vines? All of these aspects of texture factor into what kind of garden landscape you end up with.