The example of Simplilearn offer a great alignment between the elements of title, list, botton and picture that provide a simple message to the final user, the alignment help to increase the reability of the side.
Repetition
Semrush
semrush.com
This website provide a good example of repetition due to the elements have a balance between paragraph and the icon in each paragraph is clean and simple and follow the principle of repetition.
Contrast
Datacamp
Datacamp.com
One of my favorite website personally, is a good example of contrast playing with the color creating a contrast between the titles, logo, subtitles and descrition with different fonts.