The basis of good display advertising is structure. And there are established good practices that you should follow when mapping your ad. Interactive advertising manuals say that display ads should be "different from normal web page content, and the ad unit should have clear boundaries and not be confused with normal web content."
They also say that the sizing of banner ads should be flexible because people can view your ad on screens of different sizes.
Google offers a variety of ad sizes, from half-page ads to rankings to large mobile banners. The first three ad sizes in terms of performance are 300x250 (medium rectangle), 336x280 (large rectangle), and 728x90 (ranking).
So, you need to make sure that you have a strong but flexible structure that fits any format, paying special attention to the most effective dimensions.
To do this, consider the main elements of display advertising. Each ad must contain four main components:
1. Your logo or company name
2. Value proposition
3. Image or visual presentation of your service
4. CTA button