There are a lot of guidelines you can follow to make your website more ergonomic:

• The Law of Good Gestalt: Is my logo simple and easily recognizable?
• The Law of Proximity: Are my contents/clicking areas of the same type physically close?
• The Law of Similarity: Do my buttons / clickable areas look alike (Size, Shape, Color, Content, Behavior)?
• Fitts Law: Are my profitable areas big and close enough?
• Miller’s Magic Number: Do my menus and pick-lists contain between 5 and 9 items?
• Hick’s Law: Are my offers simple and in appropriate number?
• Readability of the visual language: Does my content and clickable elements stand out from the background?
• Readability of the text: Do I use a language that my users are familiar with? Do I use a readable font? Is there an interline spacing between my paragraphs? Is my text aligned left?
• Web conventions: Does my website respect the most common web conventions?

Read more here:

Make Your Website Look Like a Million Bucks! – Part 1 – Ergonomics Psychology Theories

Make Your Website Look Like A Million Bucks! – Part 2 – Readability and Web Conventions