Design is a science. As every science, it obey a set of basic principles:
Based on its size, shape and placement you will define the importance of an element. Our eye will naturally be attracted by the biggest, most irregular element of the composition. Also a center element will always appear more important. Placement will determine the hierarchy of an element.
Every design has an axis that defines its flow, like a road or a comic book (It’s doesn’t have to be a straight line). This line will define the way to read the design and align it’s different elements. Considering this flow your can define a starting point and and guide the viewer follow the line. Humans tends to follow lines when it goes in a clear direction. Knowing this you can add movement to your composition.
Humans are really good recognizing pattern. There is patterns everywhere, from songs to listing page we are expose to it all the time. When we find a pattern, our brain becomes familiar with the structure and is able to find information much faster (Ex: listing cards on real estate websites). Pattern make list and large amount of information digestible. Breaks are very important and allow to introduce new elements in the composition. Think about breaks in general, they’re here to catch your attention. A special break/cut in a movie often indicate that something special is about to happen.
A symmetrical or asymmetrical arrangement of the elements will influence the balance of a composition. In general symmetry add balance and make a layout easy to read. An asymmetrical element can create a break and grab attention but will make the layout harder to scan. Randomness or an absolute lack of symmetry can be a way to create an impactful design.
Colors have a meaning. We take very different actions based on color, most of the time without even thinking about it (Traffic light, danger sign…). Consider the color theory when you design. Color can improve the contrast to improve the readability of a design. It’s also a tool to distinguish the importance of an element.
We create proximity by grouping items together to signal that they are related. Grouping helps organizing your composition, like similarity. White space is also important to structure a layout by defining the distance between each elements.
Here you are. You now know the principles of design. This principles are what helps you execute a “good” design. They are nothing without a purpose. Wether it’s a story, a product, a few lines of text or something deeper like a feeling, a lifestyle. The success of your design will always live in your message.