Great graphic design should ‘communicate, not decorate’. What that means, is that the elements on the page should each say something about your brand, about navigating your page or about your industry. Brilliant graphic design isn’t about flourishes and random lines that are there just for show – everything should have a purpose and should be there to help inform and instruct the viewer.
If your graphic design is for advertising purposes, then its objective is also to persuade. This is why graphic design requires a good understanding of psychology – what is it that will best attract attention? What do you need to include to stir a viewer’s emotion? Moreover, what do you have to do to get them to click on your adverts?