The best design for an online business depends on the nature of the business, target audience, and marketing goals. However, here are some general guidelines for creating effective graphical designs for online businesses:

1. Keep it simple: Avoid cluttering your design with too many elements. A simple, clean design is often more effective in catching the user’s attention.
2. Use high-quality images: Use high-quality images that are relevant to your business and message. Avoid using low-resolution or blurry images, as they can create a negative impression.
3. Use colors effectively: Choose colors that are consistent with your brand and convey the right emotions. For example, blue is often associated with trust and reliability, while red is associated with excitement and energy.
4. Use typography effectively: Choose fonts that are easy to read and consistent with your brand. Avoid using too many different fonts, as it can make your design look unprofessional.
5. Make it responsive: Ensure that your design is responsive and looks good on different screen sizes, including mobile devices.
6. Use whitespace effectively: Use whitespace to create a sense of balance and to highlight important elements of your design.
7. Use visual hierarchy: Use visual hierarchy to guide the user’s attention to the most important elements of your design. This can be achieved by using size, color, and placement to create a clear hierarchy of information.

By following these guidelines, you can create effective graphical designs for your online business that help you achieve your marketing goals and engage your target audience.