To me landscaping is about creating a beautiful composition of plants whose sizes, colors, textures, and foliage compliment each other. It's not about forcing plants into certain sizes and shapes and lining them up like obedient subjects of a dictator. It's 'nature's beauty highlighted' not 'plants under oppression.'
You should give plants and trees the care they need so they can be their best selves: Prune to highlight their beauty and to remove dead/dry parts, cut branches off that might pull the plant off balance, crowd certain areas, or stifle its growth - don't just trim them down to geometric shapes (doing so will create more work for you, place undue stress on your plants, and generate more waste.)
Images from cornerstonesonoma.com