1: The contrast between the background color and the characters must be strong. For example, white characters on a black background are the strongest collocation. It is best to use dark pictures for the background color and light colors for the characters.
2. The background graphic must not be too fancy or too complicated, and the simpler the better. For example, the text is bold and bold, and the background picture is dark and single.
As mentioned above, functionality should be considered first, followed by aesthetics. This is the basic element of advertising design. This is my experience as a designer for more than ten years, and I hope I can help you.